llvm-reduce: Fix losing metadata when removing arguments

Author: arsenm

llvm/test/tools/llvm-reduce/remove-arguments-preserve-fmf.ll

@@ -16,11 +16,14 @@ declare float @math_callee_decl(float %a, float %b)
 ; INTERESTING: call
 ; INTERESTING: call
 
-; RESULT: %call0 = call nnan nsz float @math_callee()
+; RESULT: %call0 = call nnan nsz float @math_callee(), !fpmath !0
 ; RESULT: %call1 = call ninf float @math_callee_decl()
 define float @math_caller(float %x) {
-  %call0 = call nnan nsz float @math_callee(float %x, float 2.0)
+  %call0 = call nnan nsz float @math_callee(float %x, float 2.0), !fpmath !0
   %call1 = call ninf float @math_callee_decl(float %x, float 2.0)
   %result = fadd float %call0, %call1
   ret float %result
 }
+
+; RESULT: !0 = !{float 2.000000e+00}
+!0 = !{float 2.0}

llvm/tools/llvm-reduce/deltas/ReduceArguments.cpp

@@ -61,7 +61,7 @@ static void replaceFunctionCalls(Function &OldF, Function &NewF,
         }
       }
 
-      // FIXME: Losing bundles and metadata
+      // FIXME: Losing bundles
       CallInst *NewCI = CallInst::Create(&NewF, Args);
       NewCI->setCallingConv(NewF.getCallingConv());
 
@@ -78,6 +78,8 @@ static void replaceFunctionCalls(Function &OldF, Function &NewF,
       if (auto *FPOp = dyn_cast<FPMathOperator>(NewCI))
         cast<Instruction>(FPOp)->setFastMathFlags(CI->getFastMathFlags());
 
+      NewCI->copyMetadata(*CI);
+
       if (!CI->use_empty())
         CI->replaceAllUsesWith(NewCI);
       ReplaceInstWithInst(CI, NewCI);