[X86] add mayRaiseFPException flag and FPCW registers for X87 instructions

[LiuChen3]

Summary

This patch adds flag "mayRaiseFPException" , FPCW and FPSW for X87 instructions which could raise
float exception.

[RKSimon]

Test cases?

llvm/lib/Target/X86/X86InstrFPStack.td

708 ↗

(On Diff #224524)

Why did you change this? FFREE/FFREEP leave FPSW in an undefined state

[LiuChen3]

llvm/lib/Target/X86/X86InstrFPStack.td

708 ↗

(On Diff #224524)

Thanks for your review. I have added 'let Defs = [FPSW]' in class FPI.

[LiuChen3]

Add testcase to verify if x87 instructions use/def fpcw and fpcw registers.

[LiuChen3]

The Diff 226855 has some problems. This one adds testcase to verify if x87 instructions use/def fpcw and fpcw registers.

[LiuChen3]

I am sorry I updated two wrong versions. The Diff 226862 is right version.

[craig.topper]

llvm/lib/Target/X86/X86InstrFPStack.td

711 ↗

(On Diff #226862)

FNINIT also defs FPCW as far as I can tell. It reinitializes the entire X87 FPU.

719 ↗

(On Diff #226862)

I don't think this instruction updates FPSW it appears to be a mistake in the Intel SDM, but since we never generate it it probably doesn't matter.

[craig.topper]

commandeering so I can fix the FNINIT issue. And put FPCW/FPSW in consistent order in the Uses/Defs so we don't end up with two different Implicit defs lists in X86GenInstrInfo.inc

[craig.topper]

Fix FNINIT Defs. Put FPSW/FPCW in consistent order when both are used or defed.

[craig.topper]

LGTM

[thakis]

This broke CodeGen/ms-inline-asm.c' everywhere. Can you please revert?

[thakis]

Reverted in a5bf48b84c38a180cf64ef90a46988adea2de78e

[LiuChen3]

This patch fix the broken test: CodeGen/ms-inline-asm.c.

[craig.topper]

LGTM

[RKSimon]

@LiuChen3 @craig.topper This has broken EXPENSIVE_CHECKS builds, please can you take a look? http://lab.llvm.org:8011/builders/llvm-clang-x86_64-expensive-checks-ubuntu/builds/184/

llvm/test/CodeGen/X86/x87-reg-usage.mir

+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -march=x86-64 -mattr=+x87 -mattr=-sse -run-pass none -o - %s | FileCheck %s
+# This test ensures that the MIR parser parses the x87 fpcw and fpcw regs
+
+--- |
+  declare float @llvm.sqrt.f32(float)
+
+  define void @f1(float* %a, float* %b) {
+    %1 = load float, float* %a, align 4
+    %2 = load float, float* %b, align 4
+    %sub = fsub float %1, %2
+    store float %sub, float* %a, align 4
+    ret void
+  }
+
+  define void @f2(double* %a, double* %b) {
+    %1 = load double, double* %a, align 8
+    %2 = load double, double* %b, align 8
+    %add = fadd double %1, %2
+    store double %add, double* %a, align 8
+    ret void
+  }
+
+  define void @f3(x86_fp80* %a, x86_fp80* %b) {
+    %1 = load x86_fp80, x86_fp80* %a, align 16
+    %2 = load x86_fp80, x86_fp80* %b, align 16
+    %mul = fmul x86_fp80 %1, %2
+    store x86_fp80 %mul, x86_fp80* %a, align 16
+    ret void
+  }
+
+  define void @f4(float* %a, float* %b) {
+    %1 = load float, float* %a, align 4
+    %2 = load float, float* %b, align 4
+    %div = fdiv float %1, %2
+    store float %div, float* %a, align 4
+    ret void
+  }
+
+  define void @f5(float* %val, double* %ret) {
+    %1 = load float, float* %val, align 4
+    %res = fpext float %1 to double
+    store double %res, double* %ret, align 8
+    ret void
+  }
+
+  define void @f6(double* %val, float* %ret) {
+    %1 = load double, double* %val, align 8
+    %res = fptrunc double %1 to float
+    store float %res, float* %ret, align 4
+    ret void
+  }
+
+  define void @f7(float* %a) {
+    %1 = load float, float* %a, align 4
+    %res = call float @llvm.sqrt.f32(float %1)
+    store float %res, float* %a, align 4
+    ret void
+  }
+
+
+
+...
+---
+name:            f1
+alignment:       16
+tracksRegLiveness: true
+liveins:
+  - { reg: '$rdi' }
+  - { reg: '$rsi' }
+frameInfo:
+  maxAlignment:    1
+machineFunctionInfo: {}
+body:             |
+  bb.0 (%ir-block.0):
+    liveins: $rdi, $rsi
+
+    ; CHECK-LABEL: name: f1
+    ; CHECK: liveins: $rdi, $rsi
+    ; CHECK: renamable $fp0 = LD_Fp32m renamable $rdi, 1, $noreg, 0, $noreg, implicit-def dead $fpsw, implicit $fpcw :: (load 4 from %ir.a)
+    ; CHECK: renamable $fp0 = SUB_Fp32m killed renamable $fp0, killed renamable $rsi, 1, $noreg, 0, $noreg, implicit-def dead $fpsw, implicit $fpcw :: (load 4 from %ir.b)
+    ; CHECK: ST_Fp32m killed renamable $rdi, 1, $noreg, 0, $noreg, killed renamable $fp0, implicit-def dead $fpsw, implicit $fpcw :: (store 4 into %ir.a)
+    ; CHECK: RET 0
+    renamable $fp0 = LD_Fp32m renamable $rdi, 1, $noreg, 0, $noreg, implicit-def dead $fpsw, implicit $fpcw :: (load 4 from %ir.a)
+    renamable $fp0 = SUB_Fp32m killed renamable $fp0, killed renamable $rsi, 1, $noreg, 0, $noreg, implicit-def dead $fpsw, implicit $fpcw :: (load 4 from %ir.b)
+    ST_Fp32m killed renamable $rdi, 1, $noreg, 0, $noreg, killed renamable $fp0, implicit-def dead $fpsw, implicit $fpcw :: (store 4 into %ir.a)
+    RET 0
+
+...
+---
+name:            f2
+alignment:       16
+tracksRegLiveness: true
+liveins:
+  - { reg: '$rdi' }
+  - { reg: '$rsi' }
+frameInfo:
+  maxAlignment:    1
+machineFunctionInfo: {}
+body:             |
+  bb.0 (%ir-block.0):
+    liveins: $rdi, $rsi
+
+    ; CHECK-LABEL: name: f2
+    ; CHECK: liveins: $rdi, $rsi
+    ; CHECK: renamable $fp0 = LD_Fp64m renamable $rdi, 1, $noreg, 0, $noreg, implicit-def dead $fpsw, implicit $fpcw :: (load 8 from %ir.a)
+    ; CHECK: renamable $fp0 = ADD_Fp64m killed renamable $fp0, killed renamable $rsi, 1, $noreg, 0, $noreg, implicit-def dead $fpsw, implicit $fpcw :: (load 8 from %ir.b)
+    ; CHECK: ST_Fp64m killed renamable $rdi, 1, $noreg, 0, $noreg, killed renamable $fp0, implicit-def dead $fpsw, implicit $fpcw :: (store 8 into %ir.a)
+    ; CHECK: RET 0
+    renamable $fp0 = LD_Fp64m renamable $rdi, 1, $noreg, 0, $noreg, implicit-def dead $fpsw, implicit $fpcw :: (load 8 from %ir.a)
+    renamable $fp0 = ADD_Fp64m killed renamable $fp0, killed renamable $rsi, 1, $noreg, 0, $noreg, implicit-def dead $fpsw, implicit $fpcw :: (load 8 from %ir.b)
+    ST_Fp64m killed renamable $rdi, 1, $noreg, 0, $noreg, killed renamable $fp0, implicit-def dead $fpsw, implicit $fpcw :: (store 8 into %ir.a)
+    RET 0
+
+...
+---
+name:            f3
+alignment:       16
+tracksRegLiveness: true
+liveins:
+  - { reg: '$rdi' }
+  - { reg: '$rsi' }
+frameInfo:
+  maxAlignment:    1
+machineFunctionInfo: {}
+body:             |
+  bb.0 (%ir-block.0):
+    liveins: $rdi, $rsi
+
+    ; CHECK-LABEL: name: f3
+    ; CHECK: liveins: $rdi, $rsi
+    ; CHECK: renamable $fp0 = LD_Fp80m renamable $rdi, 1, $noreg, 0, $noreg, implicit-def dead $fpsw, implicit $fpcw :: (load 10 from %ir.a, align 16)
+    ; CHECK: renamable $fp1 = LD_Fp80m killed renamable $rsi, 1, $noreg, 0, $noreg, implicit-def dead $fpsw, implicit $fpcw :: (load 10 from %ir.b, align 16)
+    ; CHECK: renamable $fp0 = MUL_Fp80 killed renamable $fp0, killed renamable $fp1, implicit-def dead $fpsw, implicit $fpcw
+    ; CHECK: ST_FpP80m killed renamable $rdi, 1, $noreg, 0, $noreg, killed renamable $fp0, implicit-def dead $fpsw, implicit $fpcw :: (store 10 into %ir.a, align 16)
+    ; CHECK: RET 0
+    renamable $fp0 = LD_Fp80m renamable $rdi, 1, $noreg, 0, $noreg, implicit-def dead $fpsw, implicit $fpcw :: (load 10 from %ir.a, align 16)
+    renamable $fp1 = LD_Fp80m killed renamable $rsi, 1, $noreg, 0, $noreg, implicit-def dead $fpsw, implicit $fpcw :: (load 10 from %ir.b, align 16)
+    renamable $fp0 = MUL_Fp80 killed renamable $fp0, killed renamable $fp1, implicit-def dead $fpsw, implicit $fpcw
+    ST_FpP80m killed renamable $rdi, 1, $noreg, 0, $noreg, killed renamable $fp0, implicit-def dead $fpsw, implicit $fpcw :: (store 10 into %ir.a, align 16)
+    RET 0
+
+...
+---
+name:            f4
+alignment:       16
+tracksRegLiveness: true
+liveins:
+  - { reg: '$rdi' }
+  - { reg: '$rsi' }
+frameInfo:
+  maxAlignment:    1
+machineFunctionInfo: {}
+body:             |
+  bb.0 (%ir-block.0):
+    liveins: $rdi, $rsi
+
+    ; CHECK-LABEL: name: f4
+    ; CHECK: liveins: $rdi, $rsi
+    ; CHECK: renamable $fp0 = LD_Fp32m renamable $rdi, 1, $noreg, 0, $noreg, implicit-def dead $fpsw, implicit $fpcw :: (load 4 from %ir.a)
+    ; CHECK: renamable $fp0 = DIV_Fp32m killed renamable $fp0, killed renamable $rsi, 1, $noreg, 0, $noreg, implicit-def dead $fpsw, implicit $fpcw :: (load 4 from %ir.b)
+    ; CHECK: ST_Fp32m killed renamable $rdi, 1, $noreg, 0, $noreg, killed renamable $fp0, implicit-def dead $fpsw, implicit $fpcw :: (store 4 into %ir.a)
+    ; CHECK: RET 0
+    renamable $fp0 = LD_Fp32m renamable $rdi, 1, $noreg, 0, $noreg, implicit-def dead $fpsw, implicit $fpcw :: (load 4 from %ir.a)
+    renamable $fp0 = DIV_Fp32m killed renamable $fp0, killed renamable $rsi, 1, $noreg, 0, $noreg, implicit-def dead $fpsw, implicit $fpcw :: (load 4 from %ir.b)
+    ST_Fp32m killed renamable $rdi, 1, $noreg, 0, $noreg, killed renamable $fp0, implicit-def dead $fpsw, implicit $fpcw :: (store 4 into %ir.a)
+    RET 0
+
+...
+---
+name:            f5
+alignment:       16
+tracksRegLiveness: true
+liveins:
+  - { reg: '$rdi' }
+  - { reg: '$rsi' }
+frameInfo:
+  maxAlignment:    1
+machineFunctionInfo: {}
+body:             |
+  bb.0 (%ir-block.0):
+    liveins: $rdi, $rsi
+
+    ; CHECK-LABEL: name: f5
+    ; CHECK: liveins: $rdi, $rsi
+    ; CHECK: renamable $fp0 = LD_Fp32m64 killed renamable $rdi, 1, $noreg, 0, $noreg, implicit-def dead $fpsw, implicit $fpcw :: (load 4 from %ir.val)
+    ; CHECK: ST_Fp64m killed renamable $rsi, 1, $noreg, 0, $noreg, killed renamable $fp0, implicit-def dead $fpsw, implicit $fpcw :: (store 8 into %ir.ret)
+    ; CHECK: RET 0
+    renamable $fp0 = LD_Fp32m64 killed renamable $rdi, 1, $noreg, 0, $noreg, implicit-def dead $fpsw, implicit $fpcw :: (load 4 from %ir.val)
+    ST_Fp64m killed renamable $rsi, 1, $noreg, 0, $noreg, killed renamable $fp0, implicit-def dead $fpsw, implicit $fpcw :: (store 8 into %ir.ret)
+    RET 0
+
+...
+---
+name:            f6
+alignment:       16
+tracksRegLiveness: true
+liveins:
+  - { reg: '$rdi' }
+  - { reg: '$rsi' }
+frameInfo:
+  maxAlignment:    4
+stack:
+  - { id: 0, size: 4, alignment: 4 }
+machineFunctionInfo: {}
+body:             |
+  bb.0 (%ir-block.0):
+    liveins: $rdi, $rsi
+
+    ; CHECK-LABEL: name: f6
+    ; CHECK: liveins: $rdi, $rsi
+    ; CHECK: renamable $fp0 = LD_Fp64m killed renamable $rdi, 1, $noreg, 0, $noreg, implicit-def dead $fpsw, implicit $fpcw :: (load 8 from %ir.val)
+    ; CHECK: ST_Fp64m32 %stack.0, 1, $noreg, 0, $noreg, killed renamable $fp0, implicit-def dead $fpsw, implicit $fpcw :: (store 4 into %stack.0)
+    ; CHECK: renamable $fp0 = LD_Fp32m %stack.0, 1, $noreg, 0, $noreg, implicit-def dead $fpsw, implicit $fpcw :: (load 4 from %stack.0)
+    ; CHECK: ST_Fp32m killed renamable $rsi, 1, $noreg, 0, $noreg, killed renamable $fp0, implicit-def dead $fpsw, implicit $fpcw :: (store 4 into %ir.ret)
+    ; CHECK: RET 0
+    renamable $fp0 = LD_Fp64m killed renamable $rdi, 1, $noreg, 0, $noreg, implicit-def dead $fpsw, implicit $fpcw :: (load 8 from %ir.val)
+    ST_Fp64m32 %stack.0, 1, $noreg, 0, $noreg, killed renamable $fp0, implicit-def dead $fpsw, implicit $fpcw :: (store 4 into %stack.0)
+    renamable $fp0 = LD_Fp32m %stack.0, 1, $noreg, 0, $noreg, implicit-def dead $fpsw, implicit $fpcw :: (load 4 from %stack.0)
+    ST_Fp32m killed renamable $rsi, 1, $noreg, 0, $noreg, killed renamable $fp0, implicit-def dead $fpsw, implicit $fpcw :: (store 4 into %ir.ret)
+    RET 0
+
+...
+---
+name:            f7
+alignment:       16
+tracksRegLiveness: true
+liveins:
+  - { reg: '$rdi' }
+frameInfo:
+  maxAlignment:    1
+machineFunctionInfo: {}
+body:             |
+  bb.0 (%ir-block.0):
+    liveins: $rdi
+
+    ; CHECK-LABEL: name: f7
+    ; CHECK: liveins: $rdi
+    ; CHECK: renamable $fp0 = LD_Fp32m renamable $rdi, 1, $noreg, 0, $noreg, implicit-def dead $fpsw, implicit $fpcw :: (load 4 from %ir.a)
+    ; CHECK: renamable $fp0 = SQRT_Fp32 killed renamable $fp0, implicit-def dead $fpsw, implicit $fpcw
+    ; CHECK: ST_Fp32m killed renamable $rdi, 1, $noreg, 0, $noreg, killed renamable $fp0, implicit-def dead $fpsw, implicit $fpcw :: (store 4 into %ir.a)
+    ; CHECK: RET 0
+    renamable $fp0 = LD_Fp32m renamable $rdi, 1, $noreg, 0, $noreg, implicit-def dead $fpsw, implicit $fpcw :: (load 4 from %ir.a)
+    renamable $fp0 = SQRT_Fp32 killed renamable $fp0, implicit-def dead $fpsw, implicit $fpcw
+    ST_Fp32m killed renamable $rdi, 1, $noreg, 0, $noreg, killed renamable $fp0, implicit-def dead $fpsw, implicit $fpcw :: (store 4 into %ir.a)
+    RET 0
+
+...