[PATCH] D40594: [InstCombine] miscompile of __builtin_fmod

[Dmitry Venikov via Phabricator via cfe-commits]

Quolyk created this revision.

Motivation: https://bugs.llvm.org/show_bug.cgi?id=34870
I'm totally not sure this is correct


https://reviews.llvm.org/D40594

Files:
  lib/CodeGen/CGBuiltin.cpp
  test/CodeGen/builtins.c


Index: test/CodeGen/builtins.c
===================================================================
--- test/CodeGen/builtins.c
+++ test/CodeGen/builtins.c
@@ -253,13 +253,16 @@
   volatile long double resld;
 
   resf = __builtin_fmodf(F,F);
-  // CHECK: frem float
+  // CHECK: call float @fmodf(float %
+  // CHECK-NOT: readnone
 
   resd = __builtin_fmod(D,D);
-  // CHECK: frem double
+  // CHECK: call double @fmod(double %
+  // CHECK-NOT: readnone
 
   resld = __builtin_fmodl(LD,LD);
-  // CHECK: frem x86_fp80
+  // CHECK: call x86_fp80 @fmodl(x86_fp80 %
+  // CHECK-NOT: readnone
 
   resf = __builtin_fabsf(F);
   resd = __builtin_fabs(D);
Index: lib/CodeGen/CGBuiltin.cpp
===================================================================
--- lib/CodeGen/CGBuiltin.cpp
+++ lib/CodeGen/CGBuiltin.cpp
@@ -899,14 +899,6 @@
   case Builtin::BI__builtin_fabsl: {
     return RValue::get(emitUnaryBuiltin(*this, E, Intrinsic::fabs));
   }
-  case Builtin::BI__builtin_fmod:
-  case Builtin::BI__builtin_fmodf:
-  case Builtin::BI__builtin_fmodl: {
-    Value *Arg1 = EmitScalarExpr(E->getArg(0));
-    Value *Arg2 = EmitScalarExpr(E->getArg(1));
-    Value *Result = Builder.CreateFRem(Arg1, Arg2, "fmod");
-    return RValue::get(Result);
-  }
   case Builtin::BI__builtin_copysign:
   case Builtin::BI__builtin_copysignf:
   case Builtin::BI__builtin_copysignl: {


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