From 43b05ab4b9edece2eb1647605663076bf33cf2a8 Mon Sep 17 00:00:00 2001
From: Sanjay Patel <spatel@rotateright.com>
Date: Wed, 2 Oct 2019 12:12:02 +0000
Subject: [PATCH] [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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@373455 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Analysis/InstructionSimplify.cpp |  9 +++++++
 test/Transforms/InstSimplify/call.ll | 36 ++++++++++------------------
 2 files changed, 21 insertions(+), 24 deletions(-)

diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp
index a2c622e7905..ca00adff773 100644
--- a/lib/Analysis/InstructionSimplify.cpp
+++ b/lib/Analysis/InstructionSimplify.cpp
@@ -5186,6 +5186,15 @@ static Value *simplifyIntrinsic(CallBase *Call, const SimplifyQuery &Q) {
     }
     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;
   }
diff --git a/test/Transforms/InstSimplify/call.ll b/test/Transforms/InstSimplify/call.ll
index 3083e60cd90..2fc0841a8e1 100644
--- a/test/Transforms/InstSimplify/call.ll
+++ b/test/Transforms/InstSimplify/call.ll
@@ -747,8 +747,7 @@ declare double @llvm.fmuladd.f64(double,double,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, double %y) {
 
 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, double %y) {
 
 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, double %y) {
 
 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 %x, double %y) {
 
 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 %x, double %y) {
 
 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 %x, double %y) {
 
 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, double %y) {
 
 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, double %y) {
 
 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, double %y) {
 
 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(double %x) {
 
 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(double %x) {
 
 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
-- 
2.40.0