[llvm] r373455 - [InstSimplify] fold fma/fmuladd with a NaN or undef operand

[Sanjay Patel via llvm-commits]

Author: spatel
Date: Wed Oct  2 05:12:02 2019
New Revision: 373455

URL: http://llvm.org/viewvc/llvm-project?rev=373455&view=rev
Log:
[InstSimplify] fold fma/fmuladd with a NaN or undef operand

This is intended to be similar to the constant folding results from
D67446
and earlier, but not all operands are constant in these tests, so the
responsibility for folding is left to InstSimplify.

Differential Revision: https://reviews.llvm.org/D67721

Modified:
    llvm/trunk/lib/Analysis/InstructionSimplify.cpp
    llvm/trunk/test/Transforms/InstSimplify/call.ll

Modified: llvm/trunk/lib/Analysis/InstructionSimplify.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/InstructionSimplify.cpp?rev=373455&r1=373454&r2=373455&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/InstructionSimplify.cpp (original)
+++ llvm/trunk/lib/Analysis/InstructionSimplify.cpp Wed Oct  2 05:12:02 2019
@@ -5186,6 +5186,15 @@ static Value *simplifyIntrinsic(CallBase
     }
     return nullptr;
   }
+  case Intrinsic::fma:
+  case Intrinsic::fmuladd: {
+    Value *Op0 = Call->getArgOperand(0);
+    Value *Op1 = Call->getArgOperand(1);
+    Value *Op2 = Call->getArgOperand(2);
+    if (Value *V = simplifyFPOp({ Op0, Op1, Op2 }))
+      return V;
+    return nullptr;
+  }
   default:
     return nullptr;
   }

Modified: llvm/trunk/test/Transforms/InstSimplify/call.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstSimplify/call.ll?rev=373455&r1=373454&r2=373455&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstSimplify/call.ll (original)
+++ llvm/trunk/test/Transforms/InstSimplify/call.ll Wed Oct  2 05:12:02 2019
@@ -747,8 +747,7 @@ declare double @llvm.fmuladd.f64(double,
 
 define double @fma_undef_op0(double %x, double %y) {
 ; CHECK-LABEL: @fma_undef_op0(
-; CHECK-NEXT:    [[R:%.*]] = call double @llvm.fma.f64(double undef, double [[X:%.*]], double [[Y:%.*]])
-; CHECK-NEXT:    ret double [[R]]
+; CHECK-NEXT:    ret double 0x7FF8000000000000
 ;
   %r = call double @llvm.fma.f64(double undef, double %x, double %y)
   ret double %r
@@ -756,8 +755,7 @@ define double @fma_undef_op0(double %x,
 
 define double @fma_undef_op1(double %x, double %y) {
 ; CHECK-LABEL: @fma_undef_op1(
-; CHECK-NEXT:    [[R:%.*]] = call double @llvm.fma.f64(double [[X:%.*]], double undef, double [[Y:%.*]])
-; CHECK-NEXT:    ret double [[R]]
+; CHECK-NEXT:    ret double 0x7FF8000000000000
 ;
   %r = call double @llvm.fma.f64(double %x, double undef, double %y)
   ret double %r
@@ -765,8 +763,7 @@ define double @fma_undef_op1(double %x,
 
 define double @fma_undef_op2(double %x, double %y) {
 ; CHECK-LABEL: @fma_undef_op2(
-; CHECK-NEXT:    [[R:%.*]] = call double @llvm.fma.f64(double [[X:%.*]], double [[Y:%.*]], double undef)
-; CHECK-NEXT:    ret double [[R]]
+; CHECK-NEXT:    ret double 0x7FF8000000000000
 ;
   %r = call double @llvm.fma.f64(double %x, double %y, double undef)
   ret double %r
@@ -774,8 +771,7 @@ define double @fma_undef_op2(double %x,
 
 define double @fmuladd_undef_op0(double %x, double %y) {
 ; CHECK-LABEL: @fmuladd_undef_op0(
-; CHECK-NEXT:    [[R:%.*]] = call double @llvm.fmuladd.f64(double undef, double [[X:%.*]], double [[Y:%.*]])
-; CHECK-NEXT:    ret double [[R]]
+; CHECK-NEXT:    ret double 0x7FF8000000000000
 ;
   %r = call double @llvm.fmuladd.f64(double undef, double %x, double %y)
   ret double %r
@@ -783,8 +779,7 @@ define double @fmuladd_undef_op0(double
 
 define double @fmuladd_undef_op1(double %x, double %y) {
 ; CHECK-LABEL: @fmuladd_undef_op1(
-; CHECK-NEXT:    [[R:%.*]] = call double @llvm.fmuladd.f64(double [[X:%.*]], double undef, double [[Y:%.*]])
-; CHECK-NEXT:    ret double [[R]]
+; CHECK-NEXT:    ret double 0x7FF8000000000000
 ;
   %r = call double @llvm.fmuladd.f64(double %x, double undef, double %y)
   ret double %r
@@ -792,8 +787,7 @@ define double @fmuladd_undef_op1(double
 
 define double @fmuladd_undef_op2(double %x, double %y) {
 ; CHECK-LABEL: @fmuladd_undef_op2(
-; CHECK-NEXT:    [[R:%.*]] = call double @llvm.fmuladd.f64(double [[X:%.*]], double [[Y:%.*]], double undef)
-; CHECK-NEXT:    ret double [[R]]
+; CHECK-NEXT:    ret double 0x7FF8000000000000
 ;
   %r = call double @llvm.fmuladd.f64(double %x, double %y, double undef)
   ret double %r
@@ -801,8 +795,7 @@ define double @fmuladd_undef_op2(double
 
 define double @fma_nan_op0(double %x, double %y) {
 ; CHECK-LABEL: @fma_nan_op0(
-; CHECK-NEXT:    [[R:%.*]] = call double @llvm.fma.f64(double 0x7FF8000000000000, double [[X:%.*]], double [[Y:%.*]])
-; CHECK-NEXT:    ret double [[R]]
+; CHECK-NEXT:    ret double 0x7FF8000000000000
 ;
   %r = call double @llvm.fma.f64(double 0x7ff8000000000000, double %x, double %y)
   ret double %r
@@ -810,8 +803,7 @@ define double @fma_nan_op0(double %x, do
 
 define double @fma_nan_op1(double %x, double %y) {
 ; CHECK-LABEL: @fma_nan_op1(
-; CHECK-NEXT:    [[R:%.*]] = call double @llvm.fma.f64(double [[X:%.*]], double 0x7FF8000000000001, double [[Y:%.*]])
-; CHECK-NEXT:    ret double [[R]]
+; CHECK-NEXT:    ret double 0x7FF8000000000001
 ;
   %r = call double @llvm.fma.f64(double %x, double 0x7ff8000000000001, double %y)
   ret double %r
@@ -819,8 +811,7 @@ define double @fma_nan_op1(double %x, do
 
 define double @fma_nan_op2(double %x, double %y) {
 ; CHECK-LABEL: @fma_nan_op2(
-; CHECK-NEXT:    [[R:%.*]] = call double @llvm.fma.f64(double [[X:%.*]], double [[Y:%.*]], double 0x7FF8000000000002)
-; CHECK-NEXT:    ret double [[R]]
+; CHECK-NEXT:    ret double 0x7FF8000000000002
 ;
   %r = call double @llvm.fma.f64(double %x, double %y, double 0x7ff8000000000002)
   ret double %r
@@ -828,8 +819,7 @@ define double @fma_nan_op2(double %x, do
 
 define double @fmuladd_nan_op0_op1(double %x) {
 ; CHECK-LABEL: @fmuladd_nan_op0_op1(
-; CHECK-NEXT:    [[R:%.*]] = call double @llvm.fmuladd.f64(double 0x7FF8000000001234, double 0x7FF800000000DEAD, double [[X:%.*]])
-; CHECK-NEXT:    ret double [[R]]
+; CHECK-NEXT:    ret double 0x7FF8000000001234
 ;
   %r = call double @llvm.fmuladd.f64(double 0x7ff8000000001234, double 0x7ff800000000dead, double %x)
   ret double %r
@@ -837,8 +827,7 @@ define double @fmuladd_nan_op0_op1(doubl
 
 define double @fmuladd_nan_op0_op2(double %x) {
 ; CHECK-LABEL: @fmuladd_nan_op0_op2(
-; CHECK-NEXT:    [[R:%.*]] = call double @llvm.fmuladd.f64(double 0x7FF8000000005678, double [[X:%.*]], double 0x7FF800000000DEAD)
-; CHECK-NEXT:    ret double [[R]]
+; CHECK-NEXT:    ret double 0x7FF8000000005678
 ;
   %r = call double @llvm.fmuladd.f64(double 0x7ff8000000005678, double %x, double 0x7ff800000000dead)
   ret double %r
@@ -846,8 +835,7 @@ define double @fmuladd_nan_op0_op2(doubl
 
 define double @fmuladd_nan_op1_op2(double %x) {
 ; CHECK-LABEL: @fmuladd_nan_op1_op2(
-; CHECK-NEXT:    [[R:%.*]] = call double @llvm.fmuladd.f64(double [[X:%.*]], double 0x7FF80000AAAAAAAA, double 0x7FF800000000DEAD)
-; CHECK-NEXT:    ret double [[R]]
+; CHECK-NEXT:    ret double 0x7FF80000AAAAAAAA
 ;
   %r = call double @llvm.fmuladd.f64(double %x, double 0x7ff80000aaaaaaaa, double 0x7ff800000000dead)
   ret double %r