[X86] Add description of FXAM instruction

[sepavloff]

Summary

Previously this instruction could be used only in assembler. This change
makes it available for compiler also. Scheduling information was copied
from FTST instruction, hopefully this can be a satisfactory approximation.

[craig.topper]

FXAM appears to be two uops where FTST is one on modern Intel CPUs based on Agner Fog's data. Agner's data for some AMD CPUs shows ~20 cycles of latency.

What do you intend to use this for?

[sepavloff]

In D104853#2838797, @craig.topper wrote:

FXAM appears to be two uops where FTST is one on modern Intel CPUs based on Agner Fog's data. Agner's data for some AMD CPUs shows ~20 cycles of latency.

Could tuning scheduling for this instruction be subsequent work?

What do you intend to use this for?

This function is a convenient basis for implementation of isnan and other classification functions for fp80. Now these functions are implemented using FUCOM* instructions. They however raise exception if argument is signaling NaN, such behavior is not suitable for the classification functions.

[craig.topper]

In D104853#2838943, @sepavloff wrote:

In D104853#2838797, @craig.topper wrote:

FXAM appears to be two uops where FTST is one on modern Intel CPUs based on Agner Fog's data. Agner's data for some AMD CPUs shows ~20 cycles of latency.

Could tuning scheduling for this instruction be subsequent work?

Yes, but that 20 cycle latency on some AMD CPUs is a little concerning. X87 tends to get more and more unoptimized in modern CPUs and I'm sure what instructions show up in code factors in to those design decisions. So using an X87 instruction that compilers haven't historically used could expose unexpected performance issues.

[sepavloff]

In D104853#2838990, @craig.topper wrote:

In D104853#2838943, @sepavloff wrote:

In D104853#2838797, @craig.topper wrote:

FXAM appears to be two uops where FTST is one on modern Intel CPUs based on Agner Fog's data. Agner's data for some AMD CPUs shows ~20 cycles of latency.

Could tuning scheduling for this instruction be subsequent work?

Yes, but that 20 cycle latency on some AMD CPUs is a little concerning. X87 tends to get more and more unoptimized in modern CPUs and I'm sure what instructions show up in code factors in to those design decisions. So using an X87 instruction that compilers haven't historically used could expose unexpected performance issues.

The table of FXAM properties built from Agner Fog data:

Core	N uops	Latency	Rec. Throughput
K7	2		2
K8	2		1
K10	2		1
Bulldozer	1	20	0.5
Piledriver	1	20	0.5
Steamroller	1	26	0.5
Excavator	1	26	0.5
Zen1	1		1
Zen2	1		1
Zen3	1		0.5
Bobcat	2		2
Jaguar	2		2
Pentium		17-21
Pentium 2,3	1	2
Pentium M	1		1
Merom	1		1
Wolfdale	1		1
Nehalem	1		1
Sandy Bridge	2		2
Ivy Bridge	2		2
Haswell	2		2
Broadwell	2	6	2
SkyLake	2	6	2
SkylakeX	2	6	2
Coffee Lake	2	6	2
Ice Lake	2	6	2
Pentium 4	1	2	1
Prescott	1		1
Atom	1	1	1
Silvermont	1	7	1
Goldmont	1		1
Goldmont+	1		1
Goldmont	1		1
Knights Landing	1		1
VIA Nano 2000			41
Nano 3000	15	38	38

Number of uops vary mostly in range 1-2.

For operations on fp80 this instruction is still better than emulation, this is the main motivation for using it. Probably it is also can be useful if SSE is unavailable.

[craig.topper]

AMD's optimization manual for bulldozer only shows a 2 cycle latency. I'm not sure why Agner reports 20 unless there's some bad case for some particular input that isn't documented. A single uop taking 20 cycles sounds very strange and must be serializing the machine. I would only expect divide/sqrt to be that high from a single uop. Maybe someone can run llvm-exegesis and one of those AMD CPUs

This patch seems ok since it doesn't change codegen.

[sepavloff]

Thanks!

llvm/lib/Target/X86/X86FloatingPoint.cpp

static const TableEntry OpcodeTable[] = {
   { X86::TST_Fp64     , X86::TST_F     },
   { X86::TST_Fp80     , X86::TST_F     },
   { X86::UCOM_FpIr32  , X86::UCOM_FIr  },
   { X86::UCOM_FpIr64  , X86::UCOM_FIr  },
   { X86::UCOM_FpIr80  , X86::UCOM_FIr  },
   { X86::UCOM_Fpr32   , X86::UCOM_Fr   },
   { X86::UCOM_Fpr64   , X86::UCOM_Fr   },
   { X86::UCOM_Fpr80   , X86::UCOM_Fr   },
+  { X86::XAM_Fp32     , X86::XAM_F     },
+  { X86::XAM_Fp64     , X86::XAM_F     },
+  { X86::XAM_Fp80     , X86::XAM_F     },
 };
 
 static unsigned getConcreteOpcode(unsigned Opcode) {
   ASSERT_SORTED(OpcodeTable);
   int Opc = Lookup(OpcodeTable, Opcode);
   assert(Opc != -1 && "FP Stack instruction not in OpcodeTable!");
   return Opc;
 }

llvm/lib/Target/X86/X86InstrFPStack.td

 def TST_Fp64  : FpIf64<(outs), (ins RFP64:$src), OneArgFP, []>;
 def TST_Fp80  : FpI_<(outs), (ins RFP80:$src), OneArgFP, []>;
 } // hasSideEffects
 
 def TST_F  : FPI<0xD9, MRM_E4, (outs), (ins), "ftst">;
 } // SchedRW
 } // Uses = [FPCW], mayRaiseFPException = 1
 
+let SchedRW = [WriteFTest] in {
+def XAM_Fp32  : FpIf32<(outs), (ins RFP32:$src), OneArgFP, []>;
+def XAM_Fp64  : FpIf64<(outs), (ins RFP64:$src), OneArgFP, []>;
+def XAM_Fp80  : FpI_<(outs), (ins RFP80:$src), OneArgFP, []>;
+def XAM_F     : FPI<0xD9, MRM_E5, (outs), (ins), "fxam">;
+} // SchedRW
+
 // Versions of FP instructions that take a single memory operand.  Added for the
 //   disassembler; remove as they are included with patterns elsewhere.
 let SchedRW = [WriteFComLd], Uses = [FPCW], mayRaiseFPException = 1,
     mayLoad = 1 in {
 def FCOM32m  : FPI<0xD8, MRM2m, (outs), (ins f32mem:$src), "fcom{s}\t$src">;
 def FCOMP32m : FPI<0xD8, MRM3m, (outs), (ins f32mem:$src), "fcomp{s}\t$src">;
 
 def FCOM64m  : FPI<0xDC, MRM2m, (outs), (ins f64mem:$src), "fcom{l}\t$src">;

 
 // Operand-less floating-point instructions for the disassembler.
 let Defs = [FPSW] in
 def FNOP : I<0xD9, MRM_D0, (outs), (ins), "fnop", []>, Sched<[WriteNop]>;
 
 let SchedRW = [WriteMicrocoded] in {
 let Defs = [FPSW] in {
 def WAIT : I<0x9B, RawFrm, (outs), (ins), "wait", []>;
-def FXAM : I<0xD9, MRM_E5, (outs), (ins), "fxam", []>;
 def FDECSTP : I<0xD9, MRM_F6, (outs), (ins), "fdecstp", []>;
 def FINCSTP : I<0xD9, MRM_F7, (outs), (ins), "fincstp", []>;
 let Uses = [FPCW], mayRaiseFPException = 1 in {
 def F2XM1 : I<0xD9, MRM_F0, (outs), (ins), "f2xm1", []>;
 def FYL2X : I<0xD9, MRM_F1, (outs), (ins), "fyl2x", []>;
 def FPTAN : I<0xD9, MRM_F2, (outs), (ins), "fptan", []>;
 def FPATAN : I<0xD9, MRM_F3, (outs), (ins), "fpatan", []>;
 def FXTRACT : I<0xD9, MRM_F4, (outs), (ins), "fxtract", []>;

llvm/lib/Target/X86/X86SchedHaswell.td

 // FCOMI(P) FUCOMI(P).
 // m.
 def : InstRW<[HWWrite3P01], (instrs COM_FIPr, COM_FIr, UCOM_FIPr, UCOM_FIr)>;
 
 // FTST.
 def : InstRW<[HWWriteP1], (instregex "TST_F")>;
 
 // FXAM.
-def : InstRW<[HWWrite2P1], (instrs FXAM)>;
+def : InstRW<[HWWrite2P1], (instrs XAM_F)>;
 
 // FPREM.
 def HWWriteFPREM : SchedWriteRes<[]> {
   let Latency = 19;
   let NumMicroOps = 28;
 }
 def : InstRW<[HWWriteFPREM], (instrs FPREM)>;
 

llvm/lib/Target/X86/X86ScheduleAtom.td

 // Special Cases.
 ////////////////////////////////////////////////////////////////////////////////
 
 // Port0
 def AtomWrite0_1 : SchedWriteRes<[AtomPort0]> {
   let Latency = 1;
   let ResourceCycles = [1];
 }
-def : InstRW<[AtomWrite0_1], (instrs FXAM, LD_Frr,
+def : InstRW<[AtomWrite0_1], (instrs XAM_F, LD_Frr,
                                      MOVSX64rr32)>;
 def : SchedAlias<WriteALURMW, AtomWrite0_1>;
 def : SchedAlias<WriteADCRMW, AtomWrite0_1>;
 def : InstRW<[AtomWrite0_1], (instregex "(RCL|RCR|ROL|ROR|SAR|SHL|SHR)(8|16|32|64)m",
                                         "MOV(S|Z)X(32|64)rr(8|8_NOREX|16)")>;
 
 // Port1
 def AtomWrite1_1 : SchedWriteRes<[AtomPort1]> {

llvm/lib/Target/X86/X86ScheduleZnver1.td

 
 // FICOM(P).
 def : InstRW<[ZnWriteFPU03], (instregex "FICOM(P?)(16|32)m")>;
 
 // FTST.
 def : InstRW<[ZnWriteFPU0Lat1], (instregex "TST_F")>;
 
 // FXAM.
-def : InstRW<[ZnWriteFPU3Lat1], (instrs FXAM)>;
+def : InstRW<[ZnWriteFPU3Lat1], (instrs XAM_F)>;
 
 // FPREM.
 def : InstRW<[WriteMicrocoded], (instrs FPREM)>;
 
 // FPREM1.
 def : InstRW<[WriteMicrocoded], (instrs FPREM1)>;
 
 // FRNDINT.

llvm/lib/Target/X86/X86ScheduleZnver2.td

 
 // FICOM(P).
 def : InstRW<[Zn2WriteFPU03], (instregex "FICOM(P?)(16|32)m")>;
 
 // FTST.
 def : InstRW<[Zn2WriteFPU0Lat1], (instregex "TST_F")>;
 
 // FXAM.
-def : InstRW<[Zn2WriteFPU3Lat1], (instrs FXAM)>;
+def : InstRW<[Zn2WriteFPU3Lat1], (instrs XAM_F)>;
 
 // FPREM.
 def : InstRW<[WriteMicrocoded], (instrs FPREM)>;
 
 // FPREM1.
 def : InstRW<[WriteMicrocoded], (instrs FPREM1)>;
 
 // FRNDINT.

llvm/test/tools/llvm-mca/X86/Barcelona/resources-x87.s

 # CHECK-NEXT:  1      1     1.00                  U     fucom %st(1)
 # CHECK-NEXT:  1      1     1.00                  U     fucom %st(3)
 # CHECK-NEXT:  1      1     1.00                  U     fucomp  %st(1)
 # CHECK-NEXT:  1      1     1.00                  U     fucomp  %st(3)
 # CHECK-NEXT:  1      3     1.00                  U     fucompp
 # CHECK-NEXT:  3      3     1.00                  U     fucomi  %st(3), %st
 # CHECK-NEXT:  3      3     1.00                  U     fucompi %st(3), %st
 # CHECK-NEXT:  1      100   0.33                  U     wait
-# CHECK-NEXT:  1      100   0.33                  U     fxam
+# CHECK-NEXT:  1      1     1.00                  U     fxam
 # CHECK-NEXT:  1      1     0.33                  U     fxch  %st(1)
 # CHECK-NEXT:  1      1     0.33                  U     fxch  %st(3)
 # CHECK-NEXT:  5      5     2.00    *      *      U     fxrstor (%eax)
 # CHECK-NEXT:  1      100   0.33    *      *      U     fxsave  (%eax)
 # CHECK-NEXT:  1      100   0.33                  U     fxtract
 # CHECK-NEXT:  1      100   0.33                  U     fyl2x
 # CHECK-NEXT:  1      100   0.33                  U     fyl2xp1
 
 # CHECK:      Resources:
 # CHECK-NEXT: [0]   - SBDivider
 # CHECK-NEXT: [1]   - SBFPDivider
 # CHECK-NEXT: [2]   - SBPort0
 # CHECK-NEXT: [3]   - SBPort1
 # CHECK-NEXT: [4]   - SBPort4
 # CHECK-NEXT: [5]   - SBPort5
 # CHECK-NEXT: [6.0] - SBPort23
 # CHECK-NEXT: [6.1] - SBPort23
 
 # CHECK:      Resource pressure per iteration:
 # CHECK-NEXT: [0]    [1]    [2]    [3]    [4]    [5]    [6.0]  [6.1]
-# CHECK-NEXT:  -     136.00 52.67  90.67  17.00  54.67  34.00  34.00
+# CHECK-NEXT:  -     136.00 53.33  90.33  17.00  54.33  34.00  34.00
 
 # CHECK:      Resource pressure by instruction:
 # CHECK-NEXT: [0]    [1]    [2]    [3]    [4]    [5]    [6.0]  [6.1]  Instructions:
 # CHECK-NEXT:  -      -     0.33   0.33    -     0.33    -      -     f2xm1
 # CHECK-NEXT:  -      -      -      -      -     1.00    -      -     fabs
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -     fadd  %st, %st(1)
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -     fadd  %st(2), %st
 # CHECK-NEXT:  -      -      -     1.00    -      -     0.50   0.50   fadds (%ecx)

 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -     fucom %st(1)
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -     fucom %st(3)
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -     fucomp  %st(1)
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -     fucomp  %st(3)
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -     fucompp
 # CHECK-NEXT:  -      -     1.00   1.00    -     1.00    -      -     fucomi  %st(3), %st
 # CHECK-NEXT:  -      -     1.00   1.00    -     1.00    -      -     fucompi %st(3), %st
 # CHECK-NEXT:  -      -     0.33   0.33    -     0.33    -      -     wait
-# CHECK-NEXT:  -      -     0.33   0.33    -     0.33    -      -     fxam
+# CHECK-NEXT:  -      -     1.00    -      -      -      -      -     fxam
 # CHECK-NEXT:  -      -     0.33   0.33    -     0.33    -      -     fxch  %st(1)
 # CHECK-NEXT:  -      -     0.33   0.33    -     0.33    -      -     fxch  %st(3)
 # CHECK-NEXT:  -      -     0.50   0.50   1.00   2.00   0.50   0.50   fxrstor (%eax)
 # CHECK-NEXT:  -      -     0.33   0.33    -     0.33    -      -     fxsave  (%eax)
 # CHECK-NEXT:  -      -     0.33   0.33    -     0.33    -      -     fxtract
 # CHECK-NEXT:  -      -     0.33   0.33    -     0.33    -      -     fyl2x
 # CHECK-NEXT:  -      -     0.33   0.33    -     0.33    -      -     fyl2xp1

llvm/test/tools/llvm-mca/X86/BdVer2/resources-x87.s

 # CHECK-NEXT:  2      1     1.00                  U     fucom %st(1)
 # CHECK-NEXT:  2      1     1.00                  U     fucom %st(3)
 # CHECK-NEXT:  2      1     1.00                  U     fucomp  %st(1)
 # CHECK-NEXT:  2      1     1.00                  U     fucomp  %st(3)
 # CHECK-NEXT:  1      1     1.00                  U     fucompp
 # CHECK-NEXT:  2      1     1.00                  U     fucomi  %st(3), %st
 # CHECK-NEXT:  2      1     1.00                  U     fucompi %st(3), %st
 # CHECK-NEXT:  1      100   0.50                  U     wait
-# CHECK-NEXT:  1      100   0.50                  U     fxam
+# CHECK-NEXT:  2      1     1.00                  U     fxam
 # CHECK-NEXT:  1      1     1.00                  U     fxch  %st(1)
 # CHECK-NEXT:  1      1     1.00                  U     fxch  %st(3)
 # CHECK-NEXT:  1      100   0.50    *      *      U     fxrstor (%eax)
 # CHECK-NEXT:  1      100   0.50    *      *      U     fxsave  (%eax)
 # CHECK-NEXT:  1      100   0.50                  U     fxtract
 # CHECK-NEXT:  1      100   0.50                  U     fyl2x
 # CHECK-NEXT:  1      100   0.50                  U     fyl2xp1
 

 # CHECK-NEXT: [15]  - PdFPXBR
 # CHECK-NEXT: [16.0] - PdLoad
 # CHECK-NEXT: [16.1] - PdLoad
 # CHECK-NEXT: [17]  - PdMul
 # CHECK-NEXT: [18]  - PdStore
 
 # CHECK:      Resource pressure per iteration:
 # CHECK-NEXT: [0.0]  [0.1]  [1]    [2]    [3]    [4]    [5]    [6]    [7.0]  [7.1]  [8.0]  [8.1]  [9]    [10]   [11]   [12]   [13]   [14]   [15]   [16.0] [16.1] [17]   [18]
-# CHECK-NEXT: 55.50  55.50   -      -      -     39.50  23.50   -     224.00 224.00  -      -      -     7.00   56.00  32.00   -      -      -     49.00  49.00   -     13.00
+# CHECK-NEXT: 55.50  55.50   -      -      -     40.00  23.00   -     224.50 224.50  -      -      -     7.00   57.00  32.00   -      -      -     49.00  49.00   -     13.00
 
 # CHECK:      Resource pressure by instruction:
 # CHECK-NEXT: [0.0]  [0.1]  [1]    [2]    [3]    [4]    [5]    [6]    [7.0]  [7.1]  [8.0]  [8.1]  [9]    [10]   [11]   [12]   [13]   [14]   [15]   [16.0] [16.1] [17]   [18]   Instructions:
 # CHECK-NEXT:  -      -      -      -      -     0.50   0.50    -      -      -      -      -      -      -      -      -      -      -      -      -      -      -      -     f2xm1
 # CHECK-NEXT:  -      -      -      -      -      -      -      -     2.00   2.00    -      -      -      -      -     1.00    -      -      -      -      -      -      -     fabs
 # CHECK-NEXT:  -      -      -      -      -      -      -      -     0.50   0.50    -      -      -      -     1.00    -      -      -      -      -      -      -      -     fadd %st, %st(1)
 # CHECK-NEXT:  -      -      -      -      -      -      -      -     0.50   0.50    -      -      -      -     1.00    -      -      -      -      -      -      -      -     fadd %st(2), %st
 # CHECK-NEXT: 1.50   1.50    -      -      -      -      -      -     5.00   5.00    -      -      -      -     1.00    -      -      -      -     1.50   1.50    -      -     fadds  (%ecx)

 # CHECK-NEXT:  -      -      -      -      -     1.00    -      -     0.50   0.50    -      -      -      -     1.00    -      -      -      -      -      -      -      -     fucom  %st(1)
 # CHECK-NEXT:  -      -      -      -      -     1.00    -      -     0.50   0.50    -      -      -      -     1.00    -      -      -      -      -      -      -      -     fucom  %st(3)
 # CHECK-NEXT:  -      -      -      -      -     1.00    -      -     0.50   0.50    -      -      -      -     1.00    -      -      -      -      -      -      -      -     fucomp %st(1)
 # CHECK-NEXT:  -      -      -      -      -     1.00    -      -     0.50   0.50    -      -      -      -     1.00    -      -      -      -      -      -      -      -     fucomp %st(3)
 # CHECK-NEXT:  -      -      -      -      -      -      -      -     0.50   0.50    -      -      -      -      -     1.00    -      -      -      -      -      -      -     fucompp
 # CHECK-NEXT:  -      -      -      -      -     1.00    -      -     0.50   0.50    -      -      -      -     1.00    -      -      -      -      -      -      -      -     fucomi %st(3), %st
 # CHECK-NEXT:  -      -      -      -      -     1.00    -      -     0.50   0.50    -      -      -      -     1.00    -      -      -      -      -      -      -      -     fucompi  %st(3), %st
 # CHECK-NEXT:  -      -      -      -      -     0.50   0.50    -      -      -      -      -      -      -      -      -      -      -      -      -      -      -      -     wait
-# CHECK-NEXT:  -      -      -      -      -     0.50   0.50    -      -      -      -      -      -      -      -      -      -      -      -      -      -      -      -     fxam
+# CHECK-NEXT:  -      -      -      -      -     1.00    -      -     0.50   0.50    -      -      -      -     1.00    -      -      -      -      -      -      -      -     fxam
 # CHECK-NEXT:  -      -      -      -      -     1.00   1.00    -      -      -      -      -      -      -      -      -      -      -      -      -      -      -      -     fxch %st(1)
 # CHECK-NEXT:  -      -      -      -      -     1.00   1.00    -      -      -      -      -      -      -      -      -      -      -      -      -      -      -      -     fxch %st(3)
 # CHECK-NEXT:  -      -      -      -      -     0.50   0.50    -      -      -      -      -      -      -      -      -      -      -      -      -      -      -      -     fxrstor  (%eax)
 # CHECK-NEXT:  -      -      -      -      -     0.50   0.50    -      -      -      -      -      -      -      -      -      -      -      -      -      -      -      -     fxsave (%eax)
 # CHECK-NEXT:  -      -      -      -      -     0.50   0.50    -      -      -      -      -      -      -      -      -      -      -      -      -      -      -      -     fxtract
 # CHECK-NEXT:  -      -      -      -      -     0.50   0.50    -      -      -      -      -      -      -      -      -      -      -      -      -      -      -      -     fyl2x
 # CHECK-NEXT:  -      -      -      -      -     0.50   0.50    -      -      -      -      -      -      -      -      -      -      -      -      -      -      -      -     fyl2xp1

llvm/test/tools/llvm-mca/X86/Broadwell/resources-x87.s

 # CHECK-NEXT:  1      1     1.00                  U     fucom %st(1)
 # CHECK-NEXT:  1      1     1.00                  U     fucom %st(3)
 # CHECK-NEXT:  1      1     1.00                  U     fucomp  %st(1)
 # CHECK-NEXT:  1      1     1.00                  U     fucomp  %st(3)
 # CHECK-NEXT:  1      3     1.00                  U     fucompp
 # CHECK-NEXT:  1      3     1.00                  U     fucomi  %st(3), %st
 # CHECK-NEXT:  1      3     1.00                  U     fucompi %st(3), %st
 # CHECK-NEXT:  2      2     0.50                  U     wait
-# CHECK-NEXT:  1      100   0.25                  U     fxam
+# CHECK-NEXT:  1      1     1.00                  U     fxam
 # CHECK-NEXT:  12     14    4.00                  U     fxch  %st(1)
 # CHECK-NEXT:  12     14    4.00                  U     fxch  %st(3)
 # CHECK-NEXT:  90     63    16.50   *      *      U     fxrstor (%eax)
 # CHECK-NEXT:  1      100   0.25    *      *      U     fxsave  (%eax)
 # CHECK-NEXT:  1      100   0.25                  U     fxtract
 # CHECK-NEXT:  1      100   0.25                  U     fyl2x
 # CHECK-NEXT:  1      100   0.25                  U     fyl2xp1
 
 # CHECK:      Resources:
 # CHECK-NEXT: [0]   - BWDivider
 # CHECK-NEXT: [1]   - BWFPDivider
 # CHECK-NEXT: [2]   - BWPort0
 # CHECK-NEXT: [3]   - BWPort1
 # CHECK-NEXT: [4]   - BWPort2
 # CHECK-NEXT: [5]   - BWPort3
 # CHECK-NEXT: [6]   - BWPort4
 # CHECK-NEXT: [7]   - BWPort5
 # CHECK-NEXT: [8]   - BWPort6
 # CHECK-NEXT: [9]   - BWPort7
 
 # CHECK:      Resource pressure per iteration:
 # CHECK-NEXT: [0]    [1]    [2]    [3]    [4]    [5]    [6]    [7]    [8]    [9]
-# CHECK-NEXT:  -     9.00   116.92 145.92 49.00  49.00  27.00  59.42  69.75  9.00
+# CHECK-NEXT:  -     9.00   117.67 145.67 49.00  49.00  27.00  59.17  69.50  9.00
 
 # CHECK:      Resource pressure by instruction:
 # CHECK-NEXT: [0]    [1]    [2]    [3]    [4]    [5]    [6]    [7]    [8]    [9]    Instructions:
 # CHECK-NEXT:  -      -     0.25   0.25    -      -      -     0.25   0.25    -     f2xm1
 # CHECK-NEXT:  -      -      -      -      -      -      -     1.00    -      -     fabs
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -      -      -     fadd  %st, %st(1)
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -      -      -     fadd  %st(2), %st
 # CHECK-NEXT:  -      -      -     1.00   0.50   0.50    -      -      -      -     fadds (%ecx)

 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -      -      -     fucom %st(1)
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -      -      -     fucom %st(3)
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -      -      -     fucomp  %st(1)
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -      -      -     fucomp  %st(3)
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -      -      -     fucompp
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -      -      -     fucomi  %st(3), %st
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -      -      -     fucompi %st(3), %st
 # CHECK-NEXT:  -      -     0.50   0.50    -      -      -     0.50   0.50    -     wait
-# CHECK-NEXT:  -      -     0.25   0.25    -      -      -     0.25   0.25    -     fxam
+# CHECK-NEXT:  -      -     1.00    -      -      -      -      -      -      -     fxam
 # CHECK-NEXT:  -      -     3.25   2.25    -      -      -     1.25   5.25    -     fxch  %st(1)
 # CHECK-NEXT:  -      -     3.25   2.25    -      -      -     1.25   5.25    -     fxch  %st(3)
 # CHECK-NEXT:  -      -     17.25  12.25  16.50  16.50   -     12.75  14.75   -     fxrstor (%eax)
 # CHECK-NEXT:  -      -     0.25   0.25    -      -      -     0.25   0.25    -     fxsave  (%eax)
 # CHECK-NEXT:  -      -     0.25   0.25    -      -      -     0.25   0.25    -     fxtract
 # CHECK-NEXT:  -      -     0.25   0.25    -      -      -     0.25   0.25    -     fyl2x
 # CHECK-NEXT:  -      -     0.25   0.25    -      -      -     0.25   0.25    -     fyl2xp1

llvm/test/tools/llvm-mca/X86/BtVer2/resources-x87.s

 # CHECK-NEXT:  1      3     1.00                  U     fucom %st(1)
 # CHECK-NEXT:  1      3     1.00                  U     fucom %st(3)
 # CHECK-NEXT:  1      3     1.00                  U     fucomp  %st(1)
 # CHECK-NEXT:  1      3     1.00                  U     fucomp  %st(3)
 # CHECK-NEXT:  1      3     1.00                  U     fucompp
 # CHECK-NEXT:  1      3     1.00                  U     fucomi  %st(3), %st
 # CHECK-NEXT:  1      3     1.00                  U     fucompi %st(3), %st
 # CHECK-NEXT:  1      100   0.50                  U     wait
-# CHECK-NEXT:  1      100   0.50                  U     fxam
+# CHECK-NEXT:  1      3     1.00                  U     fxam
 # CHECK-NEXT:  1      1     0.50                  U     fxch  %st(1)
 # CHECK-NEXT:  1      1     0.50                  U     fxch  %st(3)
 # CHECK-NEXT:  1      100   0.50    *      *      U     fxrstor (%eax)
 # CHECK-NEXT:  1      100   0.50    *      *      U     fxsave  (%eax)
 # CHECK-NEXT:  1      100   0.50                  U     fxtract
 # CHECK-NEXT:  1      100   0.50                  U     fyl2x
 # CHECK-NEXT:  1      100   0.50                  U     fyl2xp1
 

 # CHECK-NEXT: [9]   - JSAGU
 # CHECK-NEXT: [10]  - JSTC
 # CHECK-NEXT: [11]  - JVALU0
 # CHECK-NEXT: [12]  - JVALU1
 # CHECK-NEXT: [13]  - JVIMUL
 
 # CHECK:      Resource pressure per iteration:
 # CHECK-NEXT: [0]    [1]    [2]    [3]    [4]    [5]    [6]    [7]    [8]    [9]    [10]   [11]   [12]   [13]
-# CHECK-NEXT: 42.00  20.00   -     54.00  349.00 54.00  34.00  39.00   -     13.00  7.00    -      -      -
+# CHECK-NEXT: 42.50  19.50   -     55.00  349.00 55.00  34.00  39.00   -     13.00  7.00    -      -      -
 
 # CHECK:      Resource pressure by instruction:
 # CHECK-NEXT: [0]    [1]    [2]    [3]    [4]    [5]    [6]    [7]    [8]    [9]    [10]   [11]   [12]   [13]   Instructions:
 # CHECK-NEXT: 0.50   0.50    -      -      -      -      -      -      -      -      -      -      -      -     f2xm1
 # CHECK-NEXT:  -      -      -      -     1.00    -     1.00    -      -      -      -      -      -      -     fabs
 # CHECK-NEXT:  -      -      -     1.00    -     1.00    -      -      -      -      -      -      -      -     fadd  %st, %st(1)
 # CHECK-NEXT:  -      -      -     1.00    -     1.00    -      -      -      -      -      -      -      -     fadd  %st(2), %st
 # CHECK-NEXT:  -      -      -     1.00    -     1.00    -     1.00    -      -      -      -      -      -     fadds (%ecx)

 # CHECK-NEXT: 1.00    -      -     1.00    -     1.00    -      -      -      -      -      -      -      -     fucom %st(1)
 # CHECK-NEXT: 1.00    -      -     1.00    -     1.00    -      -      -      -      -      -      -      -     fucom %st(3)
 # CHECK-NEXT: 1.00    -      -     1.00    -     1.00    -      -      -      -      -      -      -      -     fucomp  %st(1)
 # CHECK-NEXT: 1.00    -      -     1.00    -     1.00    -      -      -      -      -      -      -      -     fucomp  %st(3)
 # CHECK-NEXT: 1.00    -      -     1.00    -     1.00    -      -      -      -      -      -      -      -     fucompp
 # CHECK-NEXT: 1.00    -      -     1.00    -     1.00    -      -      -      -      -      -      -      -     fucomi  %st(3), %st
 # CHECK-NEXT: 1.00    -      -     1.00    -     1.00    -      -      -      -      -      -      -      -     fucompi %st(3), %st
 # CHECK-NEXT: 0.50   0.50    -      -      -      -      -      -      -      -      -      -      -      -     wait
-# CHECK-NEXT: 0.50   0.50    -      -      -      -      -      -      -      -      -      -      -      -     fxam
+# CHECK-NEXT: 1.00    -      -     1.00    -     1.00    -      -      -      -      -      -      -      -     fxam
 # CHECK-NEXT: 0.50   0.50    -      -      -      -      -      -      -      -      -      -      -      -     fxch  %st(1)
 # CHECK-NEXT: 0.50   0.50    -      -      -      -      -      -      -      -      -      -      -      -     fxch  %st(3)
 # CHECK-NEXT: 0.50   0.50    -      -      -      -      -      -      -      -      -      -      -      -     fxrstor (%eax)
 # CHECK-NEXT: 0.50   0.50    -      -      -      -      -      -      -      -      -      -      -      -     fxsave  (%eax)
 # CHECK-NEXT: 0.50   0.50    -      -      -      -      -      -      -      -      -      -      -      -     fxtract
 # CHECK-NEXT: 0.50   0.50    -      -      -      -      -      -      -      -      -      -      -      -     fyl2x
 # CHECK-NEXT: 0.50   0.50    -      -      -      -      -      -      -      -      -      -      -      -     fyl2xp1

llvm/test/tools/llvm-mca/X86/Generic/resources-x87.s

 # CHECK-NEXT:  1      1     1.00                  U     fucom %st(1)
 # CHECK-NEXT:  1      1     1.00                  U     fucom %st(3)
 # CHECK-NEXT:  1      1     1.00                  U     fucomp  %st(1)
 # CHECK-NEXT:  1      1     1.00                  U     fucomp  %st(3)
 # CHECK-NEXT:  1      3     1.00                  U     fucompp
 # CHECK-NEXT:  3      3     1.00                  U     fucomi  %st(3), %st
 # CHECK-NEXT:  3      3     1.00                  U     fucompi %st(3), %st
 # CHECK-NEXT:  1      100   0.33                  U     wait
-# CHECK-NEXT:  1      100   0.33                  U     fxam
+# CHECK-NEXT:  1      1     1.00                  U     fxam
 # CHECK-NEXT:  1      1     0.33                  U     fxch  %st(1)
 # CHECK-NEXT:  1      1     0.33                  U     fxch  %st(3)
 # CHECK-NEXT:  5      5     2.00    *      *      U     fxrstor (%eax)
 # CHECK-NEXT:  1      100   0.33    *      *      U     fxsave  (%eax)
 # CHECK-NEXT:  1      100   0.33                  U     fxtract
 # CHECK-NEXT:  1      100   0.33                  U     fyl2x
 # CHECK-NEXT:  1      100   0.33                  U     fyl2xp1
 
 # CHECK:      Resources:
 # CHECK-NEXT: [0]   - SBDivider
 # CHECK-NEXT: [1]   - SBFPDivider
 # CHECK-NEXT: [2]   - SBPort0
 # CHECK-NEXT: [3]   - SBPort1
 # CHECK-NEXT: [4]   - SBPort4
 # CHECK-NEXT: [5]   - SBPort5
 # CHECK-NEXT: [6.0] - SBPort23
 # CHECK-NEXT: [6.1] - SBPort23
 
 # CHECK:      Resource pressure per iteration:
 # CHECK-NEXT: [0]    [1]    [2]    [3]    [4]    [5]    [6.0]  [6.1]
-# CHECK-NEXT:  -     136.00 52.67  90.67  17.00  54.67  34.00  34.00
+# CHECK-NEXT:  -     136.00 53.33  90.33  17.00  54.33  34.00  34.00
 
 # CHECK:      Resource pressure by instruction:
 # CHECK-NEXT: [0]    [1]    [2]    [3]    [4]    [5]    [6.0]  [6.1]  Instructions:
 # CHECK-NEXT:  -      -     0.33   0.33    -     0.33    -      -     f2xm1
 # CHECK-NEXT:  -      -      -      -      -     1.00    -      -     fabs
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -     fadd  %st, %st(1)
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -     fadd  %st(2), %st
 # CHECK-NEXT:  -      -      -     1.00    -      -     0.50   0.50   fadds (%ecx)

 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -     fucom %st(1)
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -     fucom %st(3)
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -     fucomp  %st(1)
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -     fucomp  %st(3)
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -     fucompp
 # CHECK-NEXT:  -      -     1.00   1.00    -     1.00    -      -     fucomi  %st(3), %st
 # CHECK-NEXT:  -      -     1.00   1.00    -     1.00    -      -     fucompi %st(3), %st
 # CHECK-NEXT:  -      -     0.33   0.33    -     0.33    -      -     wait
-# CHECK-NEXT:  -      -     0.33   0.33    -     0.33    -      -     fxam
+# CHECK-NEXT:  -      -     1.00    -      -      -      -      -     fxam
 # CHECK-NEXT:  -      -     0.33   0.33    -     0.33    -      -     fxch  %st(1)
 # CHECK-NEXT:  -      -     0.33   0.33    -     0.33    -      -     fxch  %st(3)
 # CHECK-NEXT:  -      -     0.50   0.50   1.00   2.00   0.50   0.50   fxrstor (%eax)
 # CHECK-NEXT:  -      -     0.33   0.33    -     0.33    -      -     fxsave  (%eax)
 # CHECK-NEXT:  -      -     0.33   0.33    -     0.33    -      -     fxtract
 # CHECK-NEXT:  -      -     0.33   0.33    -     0.33    -      -     fyl2x
 # CHECK-NEXT:  -      -     0.33   0.33    -     0.33    -      -     fyl2xp1

llvm/test/tools/llvm-mca/X86/SLM/resources-x87.s

 # CHECK-NEXT:  1      3     1.00                  U     fucom %st(1)
 # CHECK-NEXT:  1      3     1.00                  U     fucom %st(3)
 # CHECK-NEXT:  1      3     1.00                  U     fucomp  %st(1)
 # CHECK-NEXT:  1      3     1.00                  U     fucomp  %st(3)
 # CHECK-NEXT:  1      3     1.00                  U     fucompp
 # CHECK-NEXT:  1      3     1.00                  U     fucomi  %st(3), %st
 # CHECK-NEXT:  1      3     1.00                  U     fucompi %st(3), %st
 # CHECK-NEXT:  1      100   1.00                  U     wait
-# CHECK-NEXT:  1      100   1.00                  U     fxam
+# CHECK-NEXT:  1      1     0.50                  U     fxam
 # CHECK-NEXT:  1      1     0.50                  U     fxch  %st(1)
 # CHECK-NEXT:  1      1     0.50                  U     fxch  %st(3)
 # CHECK-NEXT:  1      100   1.00    *      *      U     fxrstor (%eax)
 # CHECK-NEXT:  1      100   1.00    *      *      U     fxsave  (%eax)
 # CHECK-NEXT:  1      100   1.00                  U     fxtract
 # CHECK-NEXT:  1      100   1.00                  U     fyl2x
 # CHECK-NEXT:  1      100   1.00                  U     fyl2xp1
 
 # CHECK:      Resources:
 # CHECK-NEXT: [0]   - SLMDivider
 # CHECK-NEXT: [1]   - SLMFPDivider
 # CHECK-NEXT: [2]   - SLMFPMultiplier
 # CHECK-NEXT: [3]   - SLM_FPC_RSV0
 # CHECK-NEXT: [4]   - SLM_FPC_RSV1
 # CHECK-NEXT: [5]   - SLM_IEC_RSV0
 # CHECK-NEXT: [6]   - SLM_IEC_RSV1
 # CHECK-NEXT: [7]   - SLM_MEC_RSV
 
 # CHECK:      Resource pressure per iteration:
 # CHECK-NEXT: [0]    [1]    [2]    [3]    [4]    [5]    [6]    [7]
-# CHECK-NEXT:  -     312.00 16.00  65.00  61.00  9.50   9.50   52.00
+# CHECK-NEXT:  -     312.00 16.00  64.50  61.50  9.50   9.50   52.00
 
 # CHECK:      Resource pressure by instruction:
 # CHECK-NEXT: [0]    [1]    [2]    [3]    [4]    [5]    [6]    [7]    Instructions:
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -     f2xm1
 # CHECK-NEXT:  -      -      -     0.50   0.50    -      -      -     fabs
 # CHECK-NEXT:  -      -      -      -     1.00    -      -      -     fadd  %st, %st(1)
 # CHECK-NEXT:  -      -      -      -     1.00    -      -      -     fadd  %st(2), %st
 # CHECK-NEXT:  -      -      -      -     1.00    -      -     1.00   fadds (%ecx)

 # CHECK-NEXT:  -      -      -      -     1.00    -      -      -     fucom %st(1)
 # CHECK-NEXT:  -      -      -      -     1.00    -      -      -     fucom %st(3)
 # CHECK-NEXT:  -      -      -      -     1.00    -      -      -     fucomp  %st(1)
 # CHECK-NEXT:  -      -      -      -     1.00    -      -      -     fucomp  %st(3)
 # CHECK-NEXT:  -      -      -      -     1.00    -      -      -     fucompp
 # CHECK-NEXT:  -      -      -      -     1.00    -      -      -     fucomi  %st(3), %st
 # CHECK-NEXT:  -      -      -      -     1.00    -      -      -     fucompi %st(3), %st
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -     wait
-# CHECK-NEXT:  -      -      -     1.00    -      -      -      -     fxam
+# CHECK-NEXT:  -      -      -     0.50   0.50    -      -      -     fxam
 # CHECK-NEXT:  -      -      -      -      -     0.50   0.50    -     fxch  %st(1)
 # CHECK-NEXT:  -      -      -      -      -     0.50   0.50    -     fxch  %st(3)
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -     fxrstor (%eax)
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -     fxsave  (%eax)
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -     fxtract
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -     fyl2x
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -     fyl2xp1

llvm/test/tools/llvm-mca/X86/SandyBridge/resources-x87.s

 # CHECK-NEXT:  1      1     1.00                  U     fucom %st(1)
 # CHECK-NEXT:  1      1     1.00                  U     fucom %st(3)
 # CHECK-NEXT:  1      1     1.00                  U     fucomp  %st(1)
 # CHECK-NEXT:  1      1     1.00                  U     fucomp  %st(3)
 # CHECK-NEXT:  1      3     1.00                  U     fucompp
 # CHECK-NEXT:  3      3     1.00                  U     fucomi  %st(3), %st
 # CHECK-NEXT:  3      3     1.00                  U     fucompi %st(3), %st
 # CHECK-NEXT:  1      100   0.33                  U     wait
-# CHECK-NEXT:  1      100   0.33                  U     fxam
+# CHECK-NEXT:  1      1     1.00                  U     fxam
 # CHECK-NEXT:  1      1     0.33                  U     fxch  %st(1)
 # CHECK-NEXT:  1      1     0.33                  U     fxch  %st(3)
 # CHECK-NEXT:  5      5     2.00    *      *      U     fxrstor (%eax)
 # CHECK-NEXT:  1      100   0.33    *      *      U     fxsave  (%eax)
 # CHECK-NEXT:  1      100   0.33                  U     fxtract
 # CHECK-NEXT:  1      100   0.33                  U     fyl2x
 # CHECK-NEXT:  1      100   0.33                  U     fyl2xp1
 
 # CHECK:      Resources:
 # CHECK-NEXT: [0]   - SBDivider
 # CHECK-NEXT: [1]   - SBFPDivider
 # CHECK-NEXT: [2]   - SBPort0
 # CHECK-NEXT: [3]   - SBPort1
 # CHECK-NEXT: [4]   - SBPort4
 # CHECK-NEXT: [5]   - SBPort5
 # CHECK-NEXT: [6.0] - SBPort23
 # CHECK-NEXT: [6.1] - SBPort23
 
 # CHECK:      Resource pressure per iteration:
 # CHECK-NEXT: [0]    [1]    [2]    [3]    [4]    [5]    [6.0]  [6.1]
-# CHECK-NEXT:  -     136.00 52.67  90.67  17.00  54.67  34.00  34.00
+# CHECK-NEXT:  -     136.00 53.33  90.33  17.00  54.33  34.00  34.00
 
 # CHECK:      Resource pressure by instruction:
 # CHECK-NEXT: [0]    [1]    [2]    [3]    [4]    [5]    [6.0]  [6.1]  Instructions:
 # CHECK-NEXT:  -      -     0.33   0.33    -     0.33    -      -     f2xm1
 # CHECK-NEXT:  -      -      -      -      -     1.00    -      -     fabs
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -     fadd  %st, %st(1)
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -     fadd  %st(2), %st
 # CHECK-NEXT:  -      -      -     1.00    -      -     0.50   0.50   fadds (%ecx)

 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -     fucom %st(1)
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -     fucom %st(3)
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -     fucomp  %st(1)
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -     fucomp  %st(3)
 # CHECK-NEXT:  -      -      -     1.00    -      -      -      -     fucompp
 # CHECK-NEXT:  -      -     1.00   1.00    -     1.00    -      -     fucomi  %st(3), %st
 # CHECK-NEXT:  -      -     1.00   1.00    -     1.00    -      -     fucompi %st(3), %st
 # CHECK-NEXT:  -      -     0.33   0.33    -     0.33    -      -     wait
-# CHECK-NEXT:  -      -     0.33   0.33    -     0.33    -      -     fxam
+# CHECK-NEXT:  -      -     1.00    -      -      -      -      -     fxam
 # CHECK-NEXT:  -      -     0.33   0.33    -     0.33    -      -     fxch  %st(1)
 # CHECK-NEXT:  -      -     0.33   0.33    -     0.33    -      -     fxch  %st(3)
 # CHECK-NEXT:  -      -     0.50   0.50   1.00   2.00   0.50   0.50   fxrstor (%eax)
 # CHECK-NEXT:  -      -     0.33   0.33    -     0.33    -      -     fxsave  (%eax)
 # CHECK-NEXT:  -      -     0.33   0.33    -     0.33    -      -     fxtract
 # CHECK-NEXT:  -      -     0.33   0.33    -     0.33    -      -     fyl2x
 # CHECK-NEXT:  -      -     0.33   0.33    -     0.33    -      -     fyl2xp1

llvm/test/tools/llvm-mca/X86/SkylakeClient/resources-x87.s

 # CHECK-NEXT:  1      1     1.00                  U     fucom %st(1)
 # CHECK-NEXT:  1      1     1.00                  U     fucom %st(3)
 # CHECK-NEXT:  1      1     1.00                  U     fucomp  %st(1)
 # CHECK-NEXT:  1      1     1.00                  U     fucomp  %st(3)
 # CHECK-NEXT:  1      2     1.00                  U     fucompp
 # CHECK-NEXT:  1      2     1.00                  U     fucomi  %st(3), %st
 # CHECK-NEXT:  1      2     1.00                  U     fucompi %st(3), %st
 # CHECK-NEXT:  2      2     0.50                  U     wait
-# CHECK-NEXT:  1      100   0.25                  U     fxam
+# CHECK-NEXT:  1      2     1.00                  U     fxam
 # CHECK-NEXT:  15     17    4.00                  U     fxch  %st(1)
 # CHECK-NEXT:  15     17    4.00                  U     fxch  %st(3)
 # CHECK-NEXT:  90     63    16.50   *      *      U     fxrstor (%eax)
 # CHECK-NEXT:  1      100   0.25    *      *      U     fxsave  (%eax)
 # CHECK-NEXT:  1      100   0.25                  U     fxtract
 # CHECK-NEXT:  1      100   0.25                  U     fyl2x
 # CHECK-NEXT:  1      100   0.25                  U     fyl2xp1
 
 # CHECK:      Resources:
 # CHECK-NEXT: [0]   - SKLDivider
 # CHECK-NEXT: [1]   - SKLFPDivider
 # CHECK-NEXT: [2]   - SKLPort0
 # CHECK-NEXT: [3]   - SKLPort1
 # CHECK-NEXT: [4]   - SKLPort2
 # CHECK-NEXT: [5]   - SKLPort3
 # CHECK-NEXT: [6]   - SKLPort4
 # CHECK-NEXT: [7]   - SKLPort5
 # CHECK-NEXT: [8]   - SKLPort6
 # CHECK-NEXT: [9]   - SKLPort7
 
 # CHECK:      Resource pressure per iteration:
 # CHECK-NEXT: [0]    [1]    [2]    [3]    [4]    [5]    [6]    [7]    [8]    [9]
-# CHECK-NEXT:  -     7.00   126.75 52.25  49.00  49.00  27.00  149.75 69.25  9.00
+# CHECK-NEXT:  -     7.00   127.50 52.00  49.00  49.00  27.00  149.50 69.00  9.00
 
 # CHECK:      Resource pressure by instruction:
 # CHECK-NEXT: [0]    [1]    [2]    [3]    [4]    [5]    [6]    [7]    [8]    [9]    Instructions:
 # CHECK-NEXT:  -      -     0.25   0.25    -      -      -     0.25   0.25    -     f2xm1
 # CHECK-NEXT:  -      -     1.00    -      -      -      -      -      -      -     fabs
 # CHECK-NEXT:  -      -      -      -      -      -      -     1.00    -      -     fadd  %st, %st(1)
 # CHECK-NEXT:  -      -      -      -      -      -      -     1.00    -      -     fadd  %st(2), %st
 # CHECK-NEXT:  -      -      -      -     0.50   0.50    -     1.00    -      -     fadds (%ecx)

 # CHECK-NEXT:  -      -      -      -      -      -      -     1.00    -      -     fucom %st(1)
 # CHECK-NEXT:  -      -      -      -      -      -      -     1.00    -      -     fucom %st(3)
 # CHECK-NEXT:  -      -      -      -      -      -      -     1.00    -      -     fucomp  %st(1)
 # CHECK-NEXT:  -      -      -      -      -      -      -     1.00    -      -     fucomp  %st(3)
 # CHECK-NEXT:  -      -     1.00    -      -      -      -      -      -      -     fucompp
 # CHECK-NEXT:  -      -     1.00    -      -      -      -      -      -      -     fucomi  %st(3), %st
 # CHECK-NEXT:  -      -     1.00    -      -      -      -      -      -      -     fucompi %st(3), %st
 # CHECK-NEXT:  -      -     0.50   0.50    -      -      -     0.50   0.50    -     wait
-# CHECK-NEXT:  -      -     0.25   0.25    -      -      -     0.25   0.25    -     fxam
+# CHECK-NEXT:  -      -     1.00    -      -      -      -      -      -      -     fxam
 # CHECK-NEXT:  -      -     4.00   2.00    -      -      -     4.00   5.00    -     fxch  %st(1)
 # CHECK-NEXT:  -      -     4.00   2.00    -      -      -     4.00   5.00    -     fxch  %st(3)
 # CHECK-NEXT:  -      -     17.25  12.25  16.50  16.50   -     12.75  14.75   -     fxrstor (%eax)
 # CHECK-NEXT:  -      -     0.25   0.25    -      -      -     0.25   0.25    -     fxsave  (%eax)
 # CHECK-NEXT:  -      -     0.25   0.25    -      -      -     0.25   0.25    -     fxtract
 # CHECK-NEXT:  -      -     0.25   0.25    -      -      -     0.25   0.25    -     fyl2x
 # CHECK-NEXT:  -      -     0.25   0.25    -      -      -     0.25   0.25    -     fyl2xp1

llvm/test/tools/llvm-mca/X86/SkylakeServer/resources-x87.s

 # CHECK-NEXT:  1      1     1.00                  U     fucom %st(1)
 # CHECK-NEXT:  1      1     1.00                  U     fucom %st(3)
 # CHECK-NEXT:  1      1     1.00                  U     fucomp  %st(1)
 # CHECK-NEXT:  1      1     1.00                  U     fucomp  %st(3)
 # CHECK-NEXT:  1      2     1.00                  U     fucompp
 # CHECK-NEXT:  1      2     1.00                  U     fucomi  %st(3), %st
 # CHECK-NEXT:  1      2     1.00                  U     fucompi %st(3), %st
 # CHECK-NEXT:  2      2     0.50                  U     wait
-# CHECK-NEXT:  1      100   0.25                  U     fxam
+# CHECK-NEXT:  1      2     1.00                  U     fxam
 # CHECK-NEXT:  15     17    4.00                  U     fxch  %st(1)
 # CHECK-NEXT:  15     17    4.00                  U     fxch  %st(3)
 # CHECK-NEXT:  90     63    16.50   *      *      U     fxrstor (%eax)
 # CHECK-NEXT:  1      100   0.25    *      *      U     fxsave  (%eax)
 # CHECK-NEXT:  1      100   0.25                  U     fxtract
 # CHECK-NEXT:  1      100   0.25                  U     fyl2x
 # CHECK-NEXT:  1      100   0.25                  U     fyl2xp1
 
 # CHECK:      Resources:
 # CHECK-NEXT: [0]   - SKXDivider
 # CHECK-NEXT: [1]   - SKXFPDivider
 # CHECK-NEXT: [2]   - SKXPort0
 # CHECK-NEXT: [3]   - SKXPort1
 # CHECK-NEXT: [4]   - SKXPort2
 # CHECK-NEXT: [5]   - SKXPort3
 # CHECK-NEXT: [6]   - SKXPort4
 # CHECK-NEXT: [7]   - SKXPort5
 # CHECK-NEXT: [8]   - SKXPort6
 # CHECK-NEXT: [9]   - SKXPort7
 
 # CHECK:      Resource pressure per iteration:
 # CHECK-NEXT: [0]    [1]    [2]    [3]    [4]    [5]    [6]    [7]    [8]    [9]
-# CHECK-NEXT:  -     7.00   126.75 52.25  49.00  49.00  27.00  149.75 69.25  9.00
+# CHECK-NEXT:  -     7.00   127.50 52.00  49.00  49.00  27.00  149.50 69.00  9.00
 
 # CHECK:      Resource pressure by instruction:
 # CHECK-NEXT: [0]    [1]    [2]    [3]    [4]    [5]    [6]    [7]    [8]    [9]    Instructions:
 # CHECK-NEXT:  -      -     0.25   0.25    -      -      -     0.25   0.25    -     f2xm1
 # CHECK-NEXT:  -      -     1.00    -      -      -      -      -      -      -     fabs
 # CHECK-NEXT:  -      -      -      -      -      -      -     1.00    -      -     fadd  %st, %st(1)
 # CHECK-NEXT:  -      -      -      -      -      -      -     1.00    -      -     fadd  %st(2), %st
 # CHECK-NEXT:  -      -      -      -     0.50   0.50    -     1.00    -      -     fadds (%ecx)

 # CHECK-NEXT:  -      -      -      -      -      -      -     1.00    -      -     fucom %st(1)
 # CHECK-NEXT:  -      -      -      -      -      -      -     1.00    -      -     fucom %st(3)
 # CHECK-NEXT:  -      -      -      -      -      -      -     1.00    -      -     fucomp  %st(1)
 # CHECK-NEXT:  -      -      -      -      -      -      -     1.00    -      -     fucomp  %st(3)
 # CHECK-NEXT:  -      -     1.00    -      -      -      -      -      -      -     fucompp
 # CHECK-NEXT:  -      -     1.00    -      -      -      -      -      -      -     fucomi  %st(3), %st
 # CHECK-NEXT:  -      -     1.00    -      -      -      -      -      -      -     fucompi %st(3), %st
 # CHECK-NEXT:  -      -     0.50   0.50    -      -      -     0.50   0.50    -     wait
-# CHECK-NEXT:  -      -     0.25   0.25    -      -      -     0.25   0.25    -     fxam
+# CHECK-NEXT:  -      -     1.00    -      -      -      -      -      -      -     fxam
 # CHECK-NEXT:  -      -     4.00   2.00    -      -      -     4.00   5.00    -     fxch  %st(1)
 # CHECK-NEXT:  -      -     4.00   2.00    -      -      -     4.00   5.00    -     fxch  %st(3)
 # CHECK-NEXT:  -      -     17.25  12.25  16.50  16.50   -     12.75  14.75   -     fxrstor (%eax)
 # CHECK-NEXT:  -      -     0.25   0.25    -      -      -     0.25   0.25    -     fxsave  (%eax)
 # CHECK-NEXT:  -      -     0.25   0.25    -      -      -     0.25   0.25    -     fxtract
 # CHECK-NEXT:  -      -     0.25   0.25    -      -      -     0.25   0.25    -     fyl2x
 # CHECK-NEXT:  -      -     0.25   0.25    -      -      -     0.25   0.25    -     fyl2xp1

llvm/test/tools/llvm-mca/X86/Znver3/resources-x87.s

 # CHECK-NEXT:  1      3     1.00                  U     fucom %st(1)
 # CHECK-NEXT:  1      3     1.00                  U     fucom %st(3)
 # CHECK-NEXT:  1      3     1.00                  U     fucomp  %st(1)
 # CHECK-NEXT:  1      3     1.00                  U     fucomp  %st(3)
 # CHECK-NEXT:  1      3     1.00                  U     fucompp
 # CHECK-NEXT:  1      3     1.00                  U     fucomi  %st(3), %st
 # CHECK-NEXT:  1      3     1.00                  U     fucompi %st(3), %st
 # CHECK-NEXT:  100    100   25.00                 U     wait
-# CHECK-NEXT:  100    100   25.00                 U     fxam
+# CHECK-NEXT:  2      1     1.00                  U     fxam
 # CHECK-NEXT:  1      1     1.00                  U     fxch  %st(1)
 # CHECK-NEXT:  1      1     1.00                  U     fxch  %st(3)
 # CHECK-NEXT:  100    100   25.00   *      *      U     fxrstor (%eax)
 # CHECK-NEXT:  100    100   25.00   *      *      U     fxsave  (%eax)
 # CHECK-NEXT:  100    100   25.00                 U     fxtract
 # CHECK-NEXT:  100    100   25.00                 U     fyl2x
 # CHECK-NEXT:  100    100   25.00                 U     fyl2xp1
 

 # CHECK-NEXT: [15.0] - Zn3Load
 # CHECK-NEXT: [15.1] - Zn3Load
 # CHECK-NEXT: [15.2] - Zn3Load
 # CHECK-NEXT: [16.0] - Zn3Store
 # CHECK-NEXT: [16.1] - Zn3Store
 
 # CHECK:      Resource pressure per iteration:
 # CHECK-NEXT: [0]    [1]    [2]    [3]    [4]    [5]    [6]    [7]    [8]    [9]    [10]   [11]   [12.0] [12.1] [13]   [14.0] [14.1] [14.2] [15.0] [15.1] [15.2] [16.0] [16.1]
-# CHECK-NEXT: 10.67  10.67  10.67  886.50 886.50 886.50 886.50  -     137.00 203.00 119.00 119.00 13.50  13.50   -     24.00  24.00  24.00  15.33  15.33  15.33  13.00  13.00
+# CHECK-NEXT: 10.67  10.67  10.67  861.50 861.50 861.50 861.50  -     137.00 204.00 120.00 119.00 13.50  13.50   -     24.00  24.00  24.00  15.33  15.33  15.33  13.00  13.00
 
 # CHECK:      Resource pressure by instruction:
 # CHECK-NEXT: [0]    [1]    [2]    [3]    [4]    [5]    [6]    [7]    [8]    [9]    [10]   [11]   [12.0] [12.1] [13]   [14.0] [14.1] [14.2] [15.0] [15.1] [15.2] [16.0] [16.1] Instructions:
 # CHECK-NEXT:  -      -      -     25.00  25.00  25.00  25.00   -      -      -      -      -      -      -      -      -      -      -      -      -      -      -      -     f2xm1
 # CHECK-NEXT:  -      -      -      -      -      -      -      -     1.00   1.00    -      -      -      -      -      -      -      -      -      -      -      -      -     fabs
 # CHECK-NEXT:  -      -      -      -      -      -      -      -      -      -     0.50   0.50    -      -      -      -      -      -      -      -      -      -      -     fadd %st, %st(1)
 # CHECK-NEXT:  -      -      -      -      -      -      -      -      -      -     0.50   0.50    -      -      -      -      -      -      -      -      -      -      -     fadd %st(2), %st
 # CHECK-NEXT:  -      -      -      -      -      -      -      -      -      -     0.50   0.50   0.50   0.50    -     0.33   0.33   0.33   0.33   0.33   0.33    -      -     fadds  (%ecx)

 # CHECK-NEXT:  -      -      -      -      -      -      -      -     1.00   1.00    -      -      -      -      -      -      -      -      -      -      -      -      -     fucom  %st(1)
 # CHECK-NEXT:  -      -      -      -      -      -      -      -     1.00   1.00    -      -      -      -      -      -      -      -      -      -      -      -      -     fucom  %st(3)
 # CHECK-NEXT:  -      -      -      -      -      -      -      -     1.00   1.00    -      -      -      -      -      -      -      -      -      -      -      -      -     fucomp %st(1)
 # CHECK-NEXT:  -      -      -      -      -      -      -      -     1.00   1.00    -      -      -      -      -      -      -      -      -      -      -      -      -     fucomp %st(3)
 # CHECK-NEXT:  -      -      -      -      -      -      -      -     1.00   1.00    -      -      -      -      -      -      -      -      -      -      -      -      -     fucompp
 # CHECK-NEXT:  -      -      -      -      -      -      -      -     1.00   1.00    -      -      -      -      -      -      -      -      -      -      -      -      -     fucomi %st(3), %st
 # CHECK-NEXT:  -      -      -      -      -      -      -      -     1.00   1.00    -      -      -      -      -      -      -      -      -      -      -      -      -     fucompi  %st(3), %st
 # CHECK-NEXT:  -      -      -     25.00  25.00  25.00  25.00   -      -      -      -      -      -      -      -      -      -      -      -      -      -      -      -     wait
-# CHECK-NEXT:  -      -      -     25.00  25.00  25.00  25.00   -      -      -      -      -      -      -      -      -      -      -      -      -      -      -      -     fxam
+# CHECK-NEXT:  -      -      -      -      -      -      -      -      -     1.00   1.00    -      -      -      -      -      -      -      -      -      -      -      -     fxam
 # CHECK-NEXT:  -      -      -     1.00   1.00   1.00   1.00    -      -      -      -      -      -      -      -      -      -      -      -      -      -      -      -     fxch %st(1)
 # CHECK-NEXT:  -      -      -     1.00   1.00   1.00   1.00    -      -      -      -      -      -      -      -      -      -      -      -      -      -      -      -     fxch %st(3)
 # CHECK-NEXT:  -      -      -     25.00  25.00  25.00  25.00   -      -      -      -      -      -      -      -      -      -      -      -      -      -      -      -     fxrstor  (%eax)
 # CHECK-NEXT:  -      -      -     25.00  25.00  25.00  25.00   -      -      -      -      -      -      -      -      -      -      -      -      -      -      -      -     fxsave (%eax)
 # CHECK-NEXT:  -      -      -     25.00  25.00  25.00  25.00   -      -      -      -      -      -      -      -      -      -      -      -      -      -      -      -     fxtract
 # CHECK-NEXT:  -      -      -     25.00  25.00  25.00  25.00   -      -      -      -      -      -      -      -      -      -      -      -      -      -      -      -     fyl2x
 # CHECK-NEXT:  -      -      -     25.00  25.00  25.00  25.00   -      -      -      -      -      -      -      -      -      -      -      -      -      -      -      -     fyl2xp1