[llvm] 491ac8f - [LibCalls] Cast Char argument to 'int' before calling emitFPutC

[Bjorn Pettersson via llvm-commits]

Author: Bjorn Pettersson
Date: 2022-10-04T12:52:05+02:00
New Revision: 491ac8f3e81c5b6ecd364b560960cd63dccd3df7

URL: https://github.com/llvm/llvm-project/commit/491ac8f3e81c5b6ecd364b560960cd63dccd3df7
DIFF: https://github.com/llvm/llvm-project/commit/491ac8f3e81c5b6ecd364b560960cd63dccd3df7.diff

LOG: [LibCalls] Cast Char argument to 'int' before calling emitFPutC

The helpers in BuildLibCalls normally expect that the Value
arguments already have the correct type (matching the lib call
signature). And exception has been emitFPutC which casted the Char
argument to 'int' using CreateIntCast. This patch moves the cast to
the caller instead of doing it inside emitFPutC.

I think it makes sense to make the BuildLibCall API:s a bit
more consistent this way, despite the need to handle the int cast
in two different places now.

Differential Revision: https://reviews.llvm.org/D135066

Added: 
    

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

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/Transforms/Utils/BuildLibCalls.h b/llvm/include/llvm/Transforms/Utils/BuildLibCalls.h
index 8941ca4889ada..bb1cb07342d46 100644
--- a/llvm/include/llvm/Transforms/Utils/BuildLibCalls.h
+++ b/llvm/include/llvm/Transforms/Utils/BuildLibCalls.h
@@ -226,8 +226,8 @@ namespace llvm {
   /// Emit a call to the puts function. This assumes that Str is some pointer.
   Value *emitPutS(Value *Str, IRBuilderBase &B, const TargetLibraryInfo *TLI);
 
-  /// Emit a call to the fputc function. This assumes that Char can be casted to
-  /// int (currently assuming int is i32), and File is a pointer to FILE.
+  /// Emit a call to the fputc function. This assumes that Char is an 'int', and
+  /// File is a pointer to FILE.
   Value *emitFPutC(Value *Char, Value *File, IRBuilderBase &B,
                    const TargetLibraryInfo *TLI);
 

diff  --git a/llvm/lib/Transforms/Utils/BuildLibCalls.cpp b/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
index b55af3bb48f71..f1d1d0d4f1ef3 100644
--- a/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
@@ -1841,8 +1841,6 @@ Value *llvm::emitFPutC(Value *Char, Value *File, IRBuilderBase &B,
                                         IntTy, File->getType());
   if (File->getType()->isPointerTy())
     inferNonMandatoryLibFuncAttrs(M, FPutcName, *TLI);
-  Char = B.CreateIntCast(Char, IntTy, /*isSigned*/true,
-                         "chari");
   CallInst *CI = B.CreateCall(F, {Char, File}, FPutcName);
 
   if (const Function *Fn =

diff  --git a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
index abd5099494e51..0303831dd8fb8 100644
--- a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -3209,11 +3209,13 @@ Value *LibCallSimplifier::optimizeFPrintFString(CallInst *CI,
 
   // Decode the second character of the format string.
   if (FormatStr[1] == 'c') {
-    // fprintf(F, "%c", chr) --> fputc(chr, F)
+    // fprintf(F, "%c", chr) --> fputc((int)chr, F)
     if (!CI->getArgOperand(2)->getType()->isIntegerTy())
       return nullptr;
-    return copyFlags(
-        *CI, emitFPutC(CI->getArgOperand(2), CI->getArgOperand(0), B, TLI));
+    Type *IntTy = B.getIntNTy(TLI->getIntSize());
+    Value *V = B.CreateIntCast(CI->getArgOperand(2), IntTy, /*isSigned*/ true,
+                               "chari");
+    return copyFlags(*CI, emitFPutC(V, CI->getArgOperand(0), B, TLI));
   }
 
   if (FormatStr[1] == 's') {
@@ -3280,7 +3282,9 @@ Value *LibCallSimplifier::optimizeFWrite(CallInst *CI, IRBuilderBase &B) {
     if (Bytes == 1 && CI->use_empty()) { // fwrite(S,1,1,F) -> fputc(S[0],F)
       Value *Char = B.CreateLoad(B.getInt8Ty(),
                                  castToCStr(CI->getArgOperand(0), B), "char");
-      Value *NewCI = emitFPutC(Char, CI->getArgOperand(3), B, TLI);
+      Type *IntTy = B.getIntNTy(TLI->getIntSize());
+      Value *Cast = B.CreateIntCast(Char, IntTy, /*isSigned*/ true, "chari");
+      Value *NewCI = emitFPutC(Cast, CI->getArgOperand(3), B, TLI);
       return NewCI ? ConstantInt::get(CI->getType(), 1) : nullptr;
     }
   }