[llvm] 4ef7be9 - [SimplifyLibCalls] Directly convert fmin/fmax to intrinsics (#177988)

[via llvm-commits]

Author: Nikita Popov
Date: 2026-02-09T10:10:24Z
New Revision: 4ef7be9b80e156c59a533557e2a0d058cb91019f

URL: https://github.com/llvm/llvm-project/commit/4ef7be9b80e156c59a533557e2a0d058cb91019f
DIFF: https://github.com/llvm/llvm-project/commit/4ef7be9b80e156c59a533557e2a0d058cb91019f.diff

LOG: [SimplifyLibCalls] Directly convert fmin/fmax to intrinsics (#177988)

Drop the custom shrinking code, which we'll also do for intrinsics.
Having libcall-only optimizations is confusing, as these are typically
directly emitted as intrinsics by the frontend.

Added: 
    

Modified: 
    llvm/include/llvm/Transforms/Utils/SimplifyLibCalls.h
    llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp

Removed: 
    


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diff  --git a/llvm/include/llvm/Transforms/Utils/SimplifyLibCalls.h b/llvm/include/llvm/Transforms/Utils/SimplifyLibCalls.h
index 64d2512308935..9ba3455254f47 100644
--- a/llvm/include/llvm/Transforms/Utils/SimplifyLibCalls.h
+++ b/llvm/include/llvm/Transforms/Utils/SimplifyLibCalls.h
@@ -204,7 +204,7 @@ class LibCallSimplifier {
   Value *replacePowWithExp(CallInst *Pow, IRBuilderBase &B);
   Value *replacePowWithSqrt(CallInst *Pow, IRBuilderBase &B);
   Value *optimizeExp2(CallInst *CI, IRBuilderBase &B);
-  Value *optimizeFMinFMax(CallInst *CI, IRBuilderBase &B);
+  Value *optimizeFMinFMax(CallInst *CI, IRBuilderBase &B, Intrinsic::ID IID);
   Value *optimizeFMinimumnumFMaximumnum(CallInst *CI, IRBuilderBase &B);
   Value *optimizeLog(CallInst *CI, IRBuilderBase &B);
   Value *optimizeSqrt(CallInst *CI, IRBuilderBase &B);

diff  --git a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
index 14d82b5d8813c..d3ba4018845dd 100644
--- a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -2521,17 +2521,8 @@ Value *LibCallSimplifier::optimizeExp2(CallInst *CI, IRBuilderBase &B) {
   return Ret;
 }
 
-Value *LibCallSimplifier::optimizeFMinFMax(CallInst *CI, IRBuilderBase &B) {
-  Module *M = CI->getModule();
-
-  // If we can shrink the call to a float function rather than a double
-  // function, do that first.
-  Function *Callee = CI->getCalledFunction();
-  StringRef Name = Callee->getName();
-  if ((Name == "fmin" || Name == "fmax") && hasFloatVersion(M, Name))
-    if (Value *Ret = optimizeBinaryDoubleFP(CI, B, TLI))
-      return Ret;
-
+Value *LibCallSimplifier::optimizeFMinFMax(CallInst *CI, IRBuilderBase &B,
+                                           Intrinsic::ID IID) {
   // The LLVM intrinsics minnum/maxnum correspond to fmin/fmax. Canonicalize to
   // the intrinsics for improved optimization (for example, vectorization).
   // No-signed-zeros is implied by the definitions of fmax/fmin themselves.
@@ -2541,9 +2532,6 @@ Value *LibCallSimplifier::optimizeFMinFMax(CallInst *CI, IRBuilderBase &B) {
   // might be impractical."
   FastMathFlags FMF = CI->getFastMathFlags();
   FMF.setNoSignedZeros();
-
-  Intrinsic::ID IID = Callee->getName().starts_with("fmin") ? Intrinsic::minnum
-                                                            : Intrinsic::maxnum;
   return copyFlags(*CI, B.CreateBinaryIntrinsic(IID, CI->getArgOperand(0),
                                                 CI->getArgOperand(1), FMF));
 }
@@ -4148,10 +4136,11 @@ Value *LibCallSimplifier::optimizeFloatingPointLibCall(CallInst *CI,
   case LibFunc_fminf:
   case LibFunc_fmin:
   case LibFunc_fminl:
+    return optimizeFMinFMax(CI, Builder, Intrinsic::minnum);
   case LibFunc_fmaxf:
   case LibFunc_fmax:
   case LibFunc_fmaxl:
-    return optimizeFMinFMax(CI, Builder);
+    return optimizeFMinFMax(CI, Builder, Intrinsic::maxnum);
   case LibFunc_fminimum_numf:
   case LibFunc_fminimum_num:
   case LibFunc_fminimum_numl: