[llvm] 905abc5 - [SDAG] enable binop identity constant folds for fmul/fdiv

Sanjay Patel via llvm-commits llvm-commits at lists.llvm.org
Tue Feb 8 07:52:34 PST 2022


Author: Sanjay Patel
Date: 2022-02-08T10:52:28-05:00
New Revision: 905abc5b7db27fa26f49f668b47a57b462be24c9

URL: https://github.com/llvm/llvm-project/commit/905abc5b7db27fa26f49f668b47a57b462be24c9
DIFF: https://github.com/llvm/llvm-project/commit/905abc5b7db27fa26f49f668b47a57b462be24c9.diff

LOG: [SDAG] enable binop identity constant folds for fmul/fdiv

The test diffs are identical to D119111.

This only affects x86 currently because no other target
has an override for the TLI hook that controls this transform.

Added: 
    

Modified: 
    llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
    llvm/test/CodeGen/X86/vector-bo-select.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index f0d755c249e6..d3f6aaec459a 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -2134,6 +2134,9 @@ static SDValue foldSelectWithIdentityConstant(SDNode *N, SelectionDAG &DAG,
         return C->isZero() && C->isNegative();
       case ISD::FSUB: // X - 0.0 --> X
         return C->isZero() && !C->isNegative();
+      case ISD::FMUL: // X * 1.0 --> X
+      case ISD::FDIV: // X / 1.0 --> X
+        return C->isExactlyValue(1.0);
       }
     }
     return false;

diff  --git a/llvm/test/CodeGen/X86/vector-bo-select.ll b/llvm/test/CodeGen/X86/vector-bo-select.ll
index 63d5031e6166..74549f95a262 100644
--- a/llvm/test/CodeGen/X86/vector-bo-select.ll
+++ b/llvm/test/CodeGen/X86/vector-bo-select.ll
@@ -279,9 +279,8 @@ define <4 x float> @fmul_v4f32(<4 x i1> %b, <4 x float> noundef %x, <4 x float>
 ; AVX512VL:       # %bb.0:
 ; AVX512VL-NEXT:    vpslld $31, %xmm0, %xmm0
 ; AVX512VL-NEXT:    vptestmd %xmm0, %xmm0, %k1
-; AVX512VL-NEXT:    vbroadcastss {{.*#+}} xmm0 = [1.0E+0,1.0E+0,1.0E+0,1.0E+0]
-; AVX512VL-NEXT:    vmovaps %xmm2, %xmm0 {%k1}
-; AVX512VL-NEXT:    vmulps %xmm0, %xmm1, %xmm0
+; AVX512VL-NEXT:    vmulps %xmm2, %xmm1, %xmm1 {%k1}
+; AVX512VL-NEXT:    vmovaps %xmm1, %xmm0
 ; AVX512VL-NEXT:    retq
   %s = select <4 x i1> %b, <4 x float> %y, <4 x float> <float 1.0, float 1.0, float 1.0, float 1.0>
   %r = fmul <4 x float> %x, %s
@@ -314,9 +313,8 @@ define <8 x float> @fmul_v8f32_commute(<8 x i1> %b, <8 x float> noundef %x, <8 x
 ; AVX512VL-NEXT:    vpmovsxwd %xmm0, %ymm0
 ; AVX512VL-NEXT:    vpslld $31, %ymm0, %ymm0
 ; AVX512VL-NEXT:    vptestmd %ymm0, %ymm0, %k1
-; AVX512VL-NEXT:    vbroadcastss {{.*#+}} ymm0 = [1.0E+0,1.0E+0,1.0E+0,1.0E+0,1.0E+0,1.0E+0,1.0E+0,1.0E+0]
-; AVX512VL-NEXT:    vmovaps %ymm2, %ymm0 {%k1}
-; AVX512VL-NEXT:    vmulps %ymm1, %ymm0, %ymm0
+; AVX512VL-NEXT:    vmulps %ymm2, %ymm1, %ymm1 {%k1}
+; AVX512VL-NEXT:    vmovaps %ymm1, %ymm0
 ; AVX512VL-NEXT:    retq
   %s = select <8 x i1> %b, <8 x float> %y, <8 x float> <float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0>
   %r = fmul <8 x float> %s, %x
@@ -344,8 +342,8 @@ define <16 x float> @fmul_v16f32_swap(<16 x i1> %b, <16 x float> noundef %x, <16
 ; AVX512-NEXT:    vpmovsxbd %xmm0, %zmm0
 ; AVX512-NEXT:    vpslld $31, %zmm0, %zmm0
 ; AVX512-NEXT:    vptestmd %zmm0, %zmm0, %k1
-; AVX512-NEXT:    vbroadcastss {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %zmm2 {%k1}
 ; AVX512-NEXT:    vmulps %zmm2, %zmm1, %zmm0
+; AVX512-NEXT:    vmovaps %zmm1, %zmm0 {%k1}
 ; AVX512-NEXT:    retq
   %s = select <16 x i1> %b, <16 x float> <float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0>, <16 x float> %y
   %r = fmul <16 x float> %x, %s
@@ -373,8 +371,8 @@ define <16 x float> @fmul_v16f32_commute_swap(<16 x i1> %b, <16 x float> noundef
 ; AVX512-NEXT:    vpmovsxbd %xmm0, %zmm0
 ; AVX512-NEXT:    vpslld $31, %zmm0, %zmm0
 ; AVX512-NEXT:    vptestmd %zmm0, %zmm0, %k1
-; AVX512-NEXT:    vbroadcastss {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %zmm2 {%k1}
-; AVX512-NEXT:    vmulps %zmm1, %zmm2, %zmm0
+; AVX512-NEXT:    vmulps %zmm2, %zmm1, %zmm0
+; AVX512-NEXT:    vmovaps %zmm1, %zmm0 {%k1}
 ; AVX512-NEXT:    retq
   %s = select <16 x i1> %b, <16 x float> <float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0>, <16 x float> %y
   %r = fmul <16 x float> %s, %x
@@ -405,9 +403,8 @@ define <4 x float> @fdiv_v4f32(<4 x i1> %b, <4 x float> noundef %x, <4 x float>
 ; AVX512VL:       # %bb.0:
 ; AVX512VL-NEXT:    vpslld $31, %xmm0, %xmm0
 ; AVX512VL-NEXT:    vptestmd %xmm0, %xmm0, %k1
-; AVX512VL-NEXT:    vbroadcastss {{.*#+}} xmm0 = [1.0E+0,1.0E+0,1.0E+0,1.0E+0]
-; AVX512VL-NEXT:    vmovaps %xmm2, %xmm0 {%k1}
-; AVX512VL-NEXT:    vdivps %xmm0, %xmm1, %xmm0
+; AVX512VL-NEXT:    vdivps %xmm2, %xmm1, %xmm1 {%k1}
+; AVX512VL-NEXT:    vmovaps %xmm1, %xmm0
 ; AVX512VL-NEXT:    retq
   %s = select <4 x i1> %b, <4 x float> %y, <4 x float> <float 1.0, float 1.0, float 1.0, float 1.0>
   %r = fdiv <4 x float> %x, %s
@@ -470,8 +467,8 @@ define <16 x float> @fdiv_v16f32_swap(<16 x i1> %b, <16 x float> noundef %x, <16
 ; AVX512-NEXT:    vpmovsxbd %xmm0, %zmm0
 ; AVX512-NEXT:    vpslld $31, %zmm0, %zmm0
 ; AVX512-NEXT:    vptestmd %zmm0, %zmm0, %k1
-; AVX512-NEXT:    vbroadcastss {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %zmm2 {%k1}
 ; AVX512-NEXT:    vdivps %zmm2, %zmm1, %zmm0
+; AVX512-NEXT:    vmovaps %zmm1, %zmm0 {%k1}
 ; AVX512-NEXT:    retq
   %s = select <16 x i1> %b, <16 x float> <float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0>, <16 x float> %y
   %r = fdiv <16 x float> %x, %s
@@ -845,9 +842,7 @@ define <8 x float> @fmul_v8f32_cast_cond(i8 noundef zeroext %pb, <8 x float> nou
 ; AVX512VL-LABEL: fmul_v8f32_cast_cond:
 ; AVX512VL:       # %bb.0:
 ; AVX512VL-NEXT:    kmovw %edi, %k1
-; AVX512VL-NEXT:    vbroadcastss {{.*#+}} ymm2 = [1.0E+0,1.0E+0,1.0E+0,1.0E+0,1.0E+0,1.0E+0,1.0E+0,1.0E+0]
-; AVX512VL-NEXT:    vmovaps %ymm1, %ymm2 {%k1}
-; AVX512VL-NEXT:    vmulps %ymm2, %ymm0, %ymm0
+; AVX512VL-NEXT:    vmulps %ymm1, %ymm0, %ymm0 {%k1}
 ; AVX512VL-NEXT:    retq
   %b = bitcast i8 %pb to <8 x i1>
   %s = select <8 x i1> %b, <8 x float> %y, <8 x float> <float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0>
@@ -911,9 +906,7 @@ define <8 x double> @fmul_v8f64_cast_cond(i8 noundef zeroext %pb, <8 x double> n
 ; AVX512-LABEL: fmul_v8f64_cast_cond:
 ; AVX512:       # %bb.0:
 ; AVX512-NEXT:    kmovw %edi, %k1
-; AVX512-NEXT:    vbroadcastsd {{.*#+}} zmm2 = [1.0E+0,1.0E+0,1.0E+0,1.0E+0,1.0E+0,1.0E+0,1.0E+0,1.0E+0]
-; AVX512-NEXT:    vmovapd %zmm1, %zmm2 {%k1}
-; AVX512-NEXT:    vmulpd %zmm2, %zmm0, %zmm0
+; AVX512-NEXT:    vmulpd %zmm1, %zmm0, %zmm0 {%k1}
 ; AVX512-NEXT:    retq
   %b = bitcast i8 %pb to <8 x i1>
   %s = select <8 x i1> %b, <8 x double> %y, <8 x double> <double 1.0, double 1.0, double 1.0, double 1.0, double 1.0, double 1.0, double 1.0, double 1.0>
@@ -986,9 +979,7 @@ define <8 x float> @fdiv_v8f32_cast_cond(i8 noundef zeroext %pb, <8 x float> nou
 ; AVX512VL-LABEL: fdiv_v8f32_cast_cond:
 ; AVX512VL:       # %bb.0:
 ; AVX512VL-NEXT:    kmovw %edi, %k1
-; AVX512VL-NEXT:    vbroadcastss {{.*#+}} ymm2 = [1.0E+0,1.0E+0,1.0E+0,1.0E+0,1.0E+0,1.0E+0,1.0E+0,1.0E+0]
-; AVX512VL-NEXT:    vmovaps %ymm1, %ymm2 {%k1}
-; AVX512VL-NEXT:    vdivps %ymm2, %ymm0, %ymm0
+; AVX512VL-NEXT:    vdivps %ymm1, %ymm0, %ymm0 {%k1}
 ; AVX512VL-NEXT:    retq
   %b = bitcast i8 %pb to <8 x i1>
   %s = select <8 x i1> %b, <8 x float> %y, <8 x float> <float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0>
@@ -1052,9 +1043,7 @@ define <8 x double> @fdiv_v8f64_cast_cond(i8 noundef zeroext %pb, <8 x double> n
 ; AVX512-LABEL: fdiv_v8f64_cast_cond:
 ; AVX512:       # %bb.0:
 ; AVX512-NEXT:    kmovw %edi, %k1
-; AVX512-NEXT:    vbroadcastsd {{.*#+}} zmm2 = [1.0E+0,1.0E+0,1.0E+0,1.0E+0,1.0E+0,1.0E+0,1.0E+0,1.0E+0]
-; AVX512-NEXT:    vmovapd %zmm1, %zmm2 {%k1}
-; AVX512-NEXT:    vdivpd %zmm2, %zmm0, %zmm0
+; AVX512-NEXT:    vdivpd %zmm1, %zmm0, %zmm0 {%k1}
 ; AVX512-NEXT:    retq
   %b = bitcast i8 %pb to <8 x i1>
   %s = select <8 x i1> %b, <8 x double> %y, <8 x double> <double 1.0, double 1.0, double 1.0, double 1.0, double 1.0, double 1.0, double 1.0, double 1.0>


        


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