Add support for VSX FMA single-precision instructions to the PPC back end

[nemanjai]

Summary

This patch adds the floating point multiply-add instructions. Double precision variants already exist, single precision variants added in ISA 2.07. he following instructions are added:
xsmaddasp
xsmaddmsp
xsmsubasp
xsmsubmsp
xsnmaddasp
xsnmaddmsp
xsnmsubasp
xsnmsubmsp

[hfinkel]

Please also include tests corresponding to those in test/CodeGen/PowerPC/vsx-fma-m.ll.

lib/Target/PowerPC/PPCInstrVSX.td

1093

This line is too long (please try to keep to 80 cols). Same is true for several lines below.

[nemanjai]

I will add those tests in the next review. I'll give it a bit of time to see if any other comments need to be addressed in the next review.

lib/Target/PowerPC/PPCInstrVSX.td

1093

OK, sorry I will fix it. I just copied the corresponding double precision ones.

[wschmidt]

No comments from me beyond what Hal has already raised.

[nemanjai]

Added the missing test coverage outlined by Hal.
Also added some support for the single precision loads and stores to fast-isel as that test case involves a run with fast-isel.

[wschmidt]

The new fast-isel bits look fine to me. If Hal's comfortable with the new FMA tests, this should be ready to go.

[hfinkel]

LGTM.

[nemanjai]

Committed revision 238578.

lib/Target/PowerPC/PPCInstrVSX.td

let AddedComplexity = 400 in { // Prefer VSX patterns over non-VSX patterns.
   def XSRSQRTESP : XX2Form<60, 10,
                            (outs vssrc:$XT), (ins vssrc:$XB),
                            "xsrsqrtesp $XT, $XB", IIC_VecFP,
                            [(set f32:$XT, (PPCfrsqrte f32:$XB))]>;
   def XSSUBSP : XX3Form<60, 8,
                         (outs vssrc:$XT), (ins vssrc:$XA, vssrc:$XB),
                         "xssubsp $XT, $XA, $XB", IIC_VecFP,
                         [(set f32:$XT, (fsub f32:$XA, f32:$XB))]>;
+
+  // FMA Instructions
+  let BaseName = "XSMADDASP" in {
+  let isCommutable = 1 in
+  def XSMADDASP : XX3Form<60, 1,
+                          (outs vssrc:$XT), (ins vssrc:$XTi, vssrc:$XA, vssrc:$XB),
+                          "xsmaddasp $XT, $XA, $XB", IIC_VecFP,
+                          [(set f32:$XT, (fma f32:$XA, f32:$XB, f32:$XTi))]>,
+                          RegConstraint<"$XTi = $XT">, NoEncode<"$XTi">,
+                          AltVSXFMARel;
+  let IsVSXFMAAlt = 1 in
+  def XSMADDMSP : XX3Form<60, 9,
+                          (outs vssrc:$XT), (ins vssrc:$XTi, vssrc:$XA, vssrc:$XB),
+                          "xsmaddmsp $XT, $XA, $XB", IIC_VecFP, []>,
+                          RegConstraint<"$XTi = $XT">, NoEncode<"$XTi">,
+                          AltVSXFMARel;
+  }
+
+  let BaseName = "XSMSUBASP" in {
+  let isCommutable = 1 in
+  def XSMSUBASP : XX3Form<60, 17,
+                          (outs vssrc:$XT), (ins vssrc:$XTi, vssrc:$XA, vssrc:$XB),
+                          "xsmsubasp $XT, $XA, $XB", IIC_VecFP,
+                          [(set f32:$XT, (fma f32:$XA, f32:$XB, (fneg f32:$XTi)))]>,
+                          RegConstraint<"$XTi = $XT">, NoEncode<"$XTi">,
+                          AltVSXFMARel;
+  let IsVSXFMAAlt = 1 in
+  def XSMSUBMSP : XX3Form<60, 25,
+                          (outs vssrc:$XT), (ins vssrc:$XTi, vssrc:$XA, vssrc:$XB),
+                          "xsmsubmsp $XT, $XA, $XB", IIC_VecFP, []>,
+                          RegConstraint<"$XTi = $XT">, NoEncode<"$XTi">,
+                          AltVSXFMARel;
+  }
+
+  let BaseName = "XSNMADDASP" in {
+  let isCommutable = 1 in
+  def XSNMADDASP : XX3Form<60, 129,
+                          (outs vssrc:$XT), (ins vssrc:$XTi, vssrc:$XA, vssrc:$XB),
+                          "xsnmaddasp $XT, $XA, $XB", IIC_VecFP,
+                          [(set f32:$XT, (fneg (fma f32:$XA, f32:$XB, f32:$XTi)))]>,
+                          RegConstraint<"$XTi = $XT">, NoEncode<"$XTi">,
+                          AltVSXFMARel;
+  let IsVSXFMAAlt = 1 in
+  def XSNMADDMSP : XX3Form<60, 137,
+                          (outs vssrc:$XT), (ins vssrc:$XTi, vssrc:$XA, vssrc:$XB),
+                          "xsnmaddmsp $XT, $XA, $XB", IIC_VecFP, []>,
+                          RegConstraint<"$XTi = $XT">, NoEncode<"$XTi">,
+                          AltVSXFMARel;
+  }
+
+  let BaseName = "XSNMSUBASP" in {
+  let isCommutable = 1 in
+  def XSNMSUBASP : XX3Form<60, 145,
+                          (outs vssrc:$XT), (ins vssrc:$XTi, vssrc:$XA, vssrc:$XB),
+                          "xsnmsubasp $XT, $XA, $XB", IIC_VecFP,
+                          [(set f32:$XT, (fneg (fma f32:$XA, f32:$XB, (fneg f32:$XTi))))]>,
+                          RegConstraint<"$XTi = $XT">, NoEncode<"$XTi">,
+                          AltVSXFMARel;
+  let IsVSXFMAAlt = 1 in
+  def XSNMSUBMSP : XX3Form<60, 153,
+                          (outs vssrc:$XT), (ins vssrc:$XTi, vssrc:$XA, vssrc:$XB),
+                          "xsnmsubmsp $XT, $XA, $XB", IIC_VecFP, []>,
+                          RegConstraint<"$XTi = $XT">, NoEncode<"$XTi">,
+                          AltVSXFMARel;
+  }
 } // AddedComplexity = 400
 } // HasP8Vector
 
 let Predicates = [HasDirectMove, HasVSX] in {
   // VSX direct move instructions
   def MFVSRD : XX1_RS6_RD5_XO<31, 51, (outs g8rc:$rA), (ins vsfrc:$XT),
                               "mfvsrd $rA, $XT", IIC_VecGeneral,
                               [(set i64:$rA, (PPCmfvsr f64:$XT))]>,

test/CodeGen/PowerPC/fma.ll

 ; RUN: llc < %s -march=ppc32 -fp-contract=fast -mattr=-vsx | FileCheck %s
 ; RUN: llc < %s -mtriple=powerpc64-unknown-linux-gnu -fp-contract=fast -mattr=+vsx -mcpu=pwr7 | FileCheck -check-prefix=CHECK-VSX %s
+; RUN: llc < %s -mtriple=powerpc64-unknown-linux-gnu -fp-contract=fast -mcpu=pwr8 | FileCheck -check-prefix=CHECK-P8 %s
+; RUN: llc < %s -mtriple=powerpc64le-unknown-linux-gnu -fp-contract=fast -mcpu=pwr8 | FileCheck -check-prefix=CHECK-P8 %s
 
 declare double @dummy1(double) #0
 declare double @dummy2(double, double) #0
 declare double @dummy3(double, double, double) #0
+declare float @dummy4(float, float) #0
 
 define double @test_FMADD1(double %A, double %B, double %C) {
   %D = fmul double %A, %B   ; <double> [#uses=1]
   %E = fadd double %C, %D   ; <double> [#uses=1]
   ret double %E
 ; CHECK-LABEL: test_FMADD1:
 ; CHECK: fmadd
 ; CHECK-NEXT: blr

 ; CHECK-LABEL: test_FNMSUBS:
 ; CHECK: fnmsubs
 ; CHECK-NEXT: blr
 
 ; CHECK-VSX-LABEL: test_FNMSUBS:
 ; CHECK-VSX: fnmsubs
 ; CHECK-VSX-NEXT: blr
 }
+
+define float @test_XSMADDMSP(float %A, float %B, float %C) {
+  %D = fmul float %A, %B    ; <float> [#uses=1]
+  %E = fadd float %C, %D    ; <float> [#uses=1]
+  ret float %E
+; CHECK-P8-LABEL: test_XSMADDMSP:
+; CHECK-P8: xsmaddmsp
+; CHECK-P8-NEXT: blr
+}
+
+define float @test_XSMSUBMSP(float %A, float %B, float %C) {
+  %D = fmul float %A, %B    ; <float> [#uses=1]
+  %E = fsub float %D, %C    ; <float> [#uses=1]
+  ret float %E
+; CHECK-P8-LABEL: test_XSMSUBMSP:
+; CHECK-P8: xsmsubmsp
+; CHECK-P8-NEXT: blr
+}
+
+define float @test_XSMADDASP(float %A, float %B, float %C, float %D) {
+  %E = fmul float %A, %B  ; <float> [#uses=2]
+  %F = fadd float %E, %C  ; <float> [#uses=1]
+  %G = fsub float %E, %D  ; <float> [#uses=1]
+  %H = call float @dummy4(float %F, float %G)      ; <float> [#uses=1]
+  ret float %H
+; CHECK-P8-LABEL: test_XSMADDASP:
+; CHECK-P8: xsmaddasp
+; CHECK-P8-NEXT: xsmsubmsp
+}
+
+define float @test_XSMSUBASP(float %A, float %B, float %C, float %D) {
+  %E = fmul float %A, %B  ; <float> [#uses=2]
+  %F = fsub float %E, %C  ; <float> [#uses=1]
+  %G = fsub float %E, %D  ; <float> [#uses=1]
+  %H = call float @dummy4(float %F, float %G)      ; <float> [#uses=1]
+  ret float %H
+; CHECK-P8-LABEL: test_XSMSUBASP:
+; CHECK-P8: xsmsubasp
+; CHECK-P8-NEXT: xsmsubmsp
+}
+
+define float @test_XSNMADDMSP(float %A, float %B, float %C) {
+  %D = fmul float %A, %B    ; <float> [#uses=1]
+  %E = fadd float %D, %C    ; <float> [#uses=1]
+  %F = fsub float -0.000000e+00, %E   ; <float> [#uses=1]
+  ret float %F
+; CHECK-P8-LABEL: test_XSNMADDMSP:
+; CHECK-P8: xsnmaddmsp
+; CHECK-P8-NEXT: blr
+}
+
+define float @test_XSNMSUBMSP(float %A, float %B, float %C) {
+  %D = fmul float %A, %B    ; <float> [#uses=1]
+  %E = fsub float %D, %C    ; <float> [#uses=1]
+  %F = fsub float -0.000000e+00, %E   ; <float> [#uses=1]
+  ret float %F
+; CHECK-P8-LABEL: test_XSNMSUBMSP:
+; CHECK-P8: xsnmsubmsp
+; CHECK-P8-NEXT: blr
+}
+
+define float @test_XSNMADDASP(float %A, float %B, float %C) {
+  %D = fmul float %A, %B    ; <float> [#uses=1]
+  %E = fadd float %D, %C    ; <float> [#uses=1]
+  %F = fsub float -0.000000e+00, %E   ; <float> [#uses=1]
+  %H = call float @dummy4(float %E, float %F)      ; <float> [#uses=1]
+  ret float %F
+; CHECK-P8-LABEL: test_XSNMADDASP:
+; CHECK-P8: xsnmaddasp
+}
+
+define float @test_XSNMSUBASP(float %A, float %B, float %C) {
+  %D = fmul float %A, %B    ; <float> [#uses=1]
+  %E = fsub float %D, %C    ; <float> [#uses=1]
+  %F = fsub float -0.000000e+00, %E   ; <float> [#uses=1]
+  %H = call float @dummy4(float %E, float %F)      ; <float> [#uses=1]
+  ret float %F
+; CHECK-P8-LABEL: test_XSNMSUBASP:
+; CHECK-P8: xsnmsubasp
+}

test/MC/Disassembler/PowerPC/vsx.txt

 0xf0 0xff 0xd9 0xc4
 
 # CHECK: xsmaddadp 7, 63, 27
 0xf0 0xff 0xd9 0x0c
 
 # CHECK: xsmaddmdp 7, 63, 27
 0xf0 0xff 0xd9 0x4c
 
+# CHECK: xsmaddasp 7, 63, 27
+0xf0 0xff 0xd8 0x0c
+
+# CHECK: xsmaddmsp 7, 63, 27
+0xf0 0xff 0xd8 0x4c
+
 # CHECK: xsmaxdp 7, 63, 27
 0xf0 0xff 0xdd 0x04
 
 # CHECK: xsmindp 7, 63, 27
 0xf0 0xff 0xdd 0x44
 
 # CHECK: xsmsubadp 7, 63, 27
 0xf0 0xff 0xd9 0x8c
 
 # CHECK: xsmsubmdp 7, 63, 27
 0xf0 0xff 0xd9 0xcc
 
+# CHECK: xsmsubasp 7, 63, 27
+0xf0 0xff 0xd8 0x8c
+
+# CHECK: xsmsubmsp 7, 63, 27
+0xf0 0xff 0xd8 0xcc
+
 # CHECK: xsmulsp 7, 63, 27
 0xf0 0xff 0xd8 0x84
 
 # CHECK: xsmuldp 7, 63, 27
 0xf0 0xff 0xd9 0x84
 
 # CHECK: xsnabsdp 7, 27
 0xf0 0xe0 0xdd 0xa4
 
 # CHECK: xsnegdp 7, 27
 0xf0 0xe0 0xdd 0xe4
 
 # CHECK: xsnmaddadp 7, 63, 27
 0xf0 0xff 0xdd 0x0c
 
 # CHECK: xsnmaddmdp 7, 63, 27
 0xf0 0xff 0xdd 0x4c
 
 # CHECK: xsnmsubadp 7, 63, 27
 0xf0 0xff 0xdd 0x8c
 
 # CHECK: xsnmsubmdp 7, 63, 27
 0xf0 0xff 0xdd 0xcc
 
+# CHECK: xsnmaddasp 7, 63, 27
+0xf0 0xff 0xdc 0x0c
+
+# CHECK: xsnmaddmsp 7, 63, 27
+0xf0 0xff 0xdc 0x4c
+
+# CHECK: xsnmsubasp 7, 63, 27
+0xf0 0xff 0xdc 0x8c
+
+# CHECK: xsnmsubmsp 7, 63, 27
+0xf0 0xff 0xdc 0xcc
+
 # CHECK: xsrdpi 7, 27
 0xf0 0xe0 0xd9 0x24
 
 # CHECK: xsrdpic 7, 27
 0xf0 0xe0 0xd9 0xac
 
 # CHECK: xsrdpim 7, 27
 0xf0 0xe0 0xd9 0xe4

test/MC/PowerPC/vsx.s

 # CHECK-LE: xsdivdp 7, 63, 27                  # encoding: [0xc4,0xd9,0xff,0xf0]
             xsdivdp 7, 63, 27
 # CHECK-BE: xsmaddadp 7, 63, 27                # encoding: [0xf0,0xff,0xd9,0x0c]
 # CHECK-LE: xsmaddadp 7, 63, 27                # encoding: [0x0c,0xd9,0xff,0xf0]
             xsmaddadp 7, 63, 27
 # CHECK-BE: xsmaddmdp 7, 63, 27                # encoding: [0xf0,0xff,0xd9,0x4c]
 # CHECK-LE: xsmaddmdp 7, 63, 27                # encoding: [0x4c,0xd9,0xff,0xf0]
             xsmaddmdp 7, 63, 27
+# CHECK-BE: xsmaddasp 7, 63, 27                # encoding: [0xf0,0xff,0xd8,0x0c]
+# CHECK-LE: xsmaddasp 7, 63, 27                # encoding: [0x0c,0xd8,0xff,0xf0]
+            xsmaddasp 7, 63, 27
+# CHECK-BE: xsmaddmsp 7, 63, 27                # encoding: [0xf0,0xff,0xd8,0x4c]
+# CHECK-LE: xsmaddmsp 7, 63, 27                # encoding: [0x4c,0xd8,0xff,0xf0]
+            xsmaddmsp 7, 63, 27
 # CHECK-BE: xsmaxdp 7, 63, 27                  # encoding: [0xf0,0xff,0xdd,0x04]
 # CHECK-LE: xsmaxdp 7, 63, 27                  # encoding: [0x04,0xdd,0xff,0xf0]
             xsmaxdp 7, 63, 27
 # CHECK-BE: xsmindp 7, 63, 27                  # encoding: [0xf0,0xff,0xdd,0x44]
 # CHECK-LE: xsmindp 7, 63, 27                  # encoding: [0x44,0xdd,0xff,0xf0]
             xsmindp 7, 63, 27
 # CHECK-BE: xsmsubadp 7, 63, 27                # encoding: [0xf0,0xff,0xd9,0x8c]
 # CHECK-LE: xsmsubadp 7, 63, 27                # encoding: [0x8c,0xd9,0xff,0xf0]
             xsmsubadp 7, 63, 27
 # CHECK-BE: xsmsubmdp 7, 63, 27                # encoding: [0xf0,0xff,0xd9,0xcc]
 # CHECK-LE: xsmsubmdp 7, 63, 27                # encoding: [0xcc,0xd9,0xff,0xf0]
             xsmsubmdp 7, 63, 27
+# CHECK-BE: xsmsubasp 7, 63, 27                # encoding: [0xf0,0xff,0xd8,0x8c]
+# CHECK-LE: xsmsubasp 7, 63, 27                # encoding: [0x8c,0xd8,0xff,0xf0]
+            xsmsubasp 7, 63, 27
+# CHECK-BE: xsmsubmsp 7, 63, 27                # encoding: [0xf0,0xff,0xd8,0xcc]
+# CHECK-LE: xsmsubmsp 7, 63, 27                # encoding: [0xcc,0xd8,0xff,0xf0]
+            xsmsubmsp 7, 63, 27
 # CHECK-BE: xsmulsp 7, 63, 27                  # encoding: [0xf0,0xff,0xd8,0x84]
 # CHECK-LE: xsmulsp 7, 63, 27                  # encoding: [0x84,0xd8,0xff,0xf0]
             xsmulsp 7, 63, 27
 # CHECK-BE: xsmuldp 7, 63, 27                  # encoding: [0xf0,0xff,0xd9,0x84]
 # CHECK-LE: xsmuldp 7, 63, 27                  # encoding: [0x84,0xd9,0xff,0xf0]
             xsmuldp 7, 63, 27
 # CHECK-BE: xsnabsdp 7, 27                     # encoding: [0xf0,0xe0,0xdd,0xa4]
 # CHECK-LE: xsnabsdp 7, 27                     # encoding: [0xa4,0xdd,0xe0,0xf0]
             xsnabsdp 7, 27
 # CHECK-BE: xsnegdp 7, 27                      # encoding: [0xf0,0xe0,0xdd,0xe4]
 # CHECK-LE: xsnegdp 7, 27                      # encoding: [0xe4,0xdd,0xe0,0xf0]
             xsnegdp 7, 27
 # CHECK-BE: xsnmaddadp 7, 63, 27               # encoding: [0xf0,0xff,0xdd,0x0c]
 # CHECK-LE: xsnmaddadp 7, 63, 27               # encoding: [0x0c,0xdd,0xff,0xf0]
             xsnmaddadp 7, 63, 27
 # CHECK-BE: xsnmaddmdp 7, 63, 27               # encoding: [0xf0,0xff,0xdd,0x4c]
 # CHECK-LE: xsnmaddmdp 7, 63, 27               # encoding: [0x4c,0xdd,0xff,0xf0]
             xsnmaddmdp 7, 63, 27
 # CHECK-BE: xsnmsubadp 7, 63, 27               # encoding: [0xf0,0xff,0xdd,0x8c]
 # CHECK-LE: xsnmsubadp 7, 63, 27               # encoding: [0x8c,0xdd,0xff,0xf0]
             xsnmsubadp 7, 63, 27
 # CHECK-BE: xsnmsubmdp 7, 63, 27               # encoding: [0xf0,0xff,0xdd,0xcc]
 # CHECK-LE: xsnmsubmdp 7, 63, 27               # encoding: [0xcc,0xdd,0xff,0xf0]
             xsnmsubmdp 7, 63, 27
+# CHECK-BE: xsnmaddasp 7, 63, 27               # encoding: [0xf0,0xff,0xdc,0x0c]
+# CHECK-LE: xsnmaddasp 7, 63, 27               # encoding: [0x0c,0xdc,0xff,0xf0]
+            xsnmaddasp 7, 63, 27
+# CHECK-BE: xsnmaddmsp 7, 63, 27               # encoding: [0xf0,0xff,0xdc,0x4c]
+# CHECK-LE: xsnmaddmsp 7, 63, 27               # encoding: [0x4c,0xdc,0xff,0xf0]
+            xsnmaddmsp 7, 63, 27
+# CHECK-BE: xsnmsubasp 7, 63, 27               # encoding: [0xf0,0xff,0xdc,0x8c]
+# CHECK-LE: xsnmsubasp 7, 63, 27               # encoding: [0x8c,0xdc,0xff,0xf0]
+            xsnmsubasp 7, 63, 27
+# CHECK-BE: xsnmsubmsp 7, 63, 27               # encoding: [0xf0,0xff,0xdc,0xcc]
+# CHECK-LE: xsnmsubmsp 7, 63, 27               # encoding: [0xcc,0xdc,0xff,0xf0]
+            xsnmsubmsp 7, 63, 27
 # CHECK-BE: xsrdpi 7, 27                       # encoding: [0xf0,0xe0,0xd9,0x24]
 # CHECK-LE: xsrdpi 7, 27                       # encoding: [0x24,0xd9,0xe0,0xf0]
             xsrdpi 7, 27
 # CHECK-BE: xsrdpic 7, 27                      # encoding: [0xf0,0xe0,0xd9,0xac]
 # CHECK-LE: xsrdpic 7, 27                      # encoding: [0xac,0xd9,0xe0,0xf0]
             xsrdpic 7, 27
 # CHECK-BE: xsrdpim 7, 27                      # encoding: [0xf0,0xe0,0xd9,0xe4]
 # CHECK-LE: xsrdpim 7, 27                      # encoding: [0xe4,0xd9,0xe0,0xf0]