[llvm] caa0e42 - Fix assertion failure in PR98681 (#98860)

[via llvm-commits]

Author: Yingwei Zheng
Date: 2024-07-15T14:59:16+08:00
New Revision: caa0e42ceb6e671d68b8b8e1d04f136696a4228b

URL: https://github.com/llvm/llvm-project/commit/caa0e42ceb6e671d68b8b8e1d04f136696a4228b
DIFF: https://github.com/llvm/llvm-project/commit/caa0e42ceb6e671d68b8b8e1d04f136696a4228b.diff

LOG: Fix assertion failure in PR98681 (#98860)

See https://en.cppreference.com/w/cpp/numeric/math/pow:
```
C++98 added overloads where exp has type int on top of C [pow()](https://en.cppreference.com/w/c/numeric/math/pow), and the return type of std::pow(float, int) was float. However, the additional overloads introduced in C++11 specify that std::pow(float, int) should return double. [LWG issue 550](https://cplusplus.github.io/LWG/issue550) was raised to target this conflict, and the resolution is to removed the extra int exp overloads.
```

Added: 
    

Modified: 
    llvm/lib/Analysis/ConstantFolding.cpp
    llvm/test/Transforms/EarlyCSE/math-2.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Analysis/ConstantFolding.cpp b/llvm/lib/Analysis/ConstantFolding.cpp
index 6c52091cd5d75..df75745645e04 100644
--- a/llvm/lib/Analysis/ConstantFolding.cpp
+++ b/llvm/lib/Analysis/ConstantFolding.cpp
@@ -2759,7 +2759,7 @@ static Constant *ConstantFoldIntrinsicCall2(Intrinsic::ID IntrinsicID, Type *Ty,
         switch (Ty->getTypeID()) {
         case Type::HalfTyID:
         case Type::FloatTyID: {
-          APFloat Res(std::pow(Op1V.convertToFloat(), Exp));
+          APFloat Res(static_cast<float>(std::pow(Op1V.convertToFloat(), Exp)));
           if (Ty->isHalfTy()) {
             bool Unused;
             Res.convert(APFloat::IEEEhalf(), APFloat::rmNearestTiesToEven,

diff  --git a/llvm/test/Transforms/EarlyCSE/math-2.ll b/llvm/test/Transforms/EarlyCSE/math-2.ll
index 60a2f19084c83..0d55165e3662f 100644
--- a/llvm/test/Transforms/EarlyCSE/math-2.ll
+++ b/llvm/test/Transforms/EarlyCSE/math-2.ll
@@ -108,4 +108,12 @@ define half @pr98665() {
   ret half %x
 }
 
+define float @powi_f32() {
+; CHECK-LABEL: @powi_f32(
+; CHECK-NEXT:    ret float 0.000000e+00
+;
+  %y = call float @llvm.powi.f32.i32(float 0.0, i32 10)
+  ret float %y
+}
+
 attributes #0 = { nofree nounwind willreturn }