commit 7233344c2800cf785ead332f89d0d4d6020760b8
author Matt Arsenault <Matthew.Arsenault@amd.com> Tue Jan 17 00:10:40 2017 +0000
committer Matt Arsenault <Matthew.Arsenault@amd.com> Tue Jan 17 00:10:40 2017 +0000
tree 85040896f45b62ffa6dbc8dda7ffbf6ebc0f218c
parent 1825a03f727181d4c35fd2229668f0b19506cfb9

SimplifyLibCalls: Replace fabs libcalls with intrinsics

Add missing fabs(fpext) optimzation that worked with the call,
and also fixes it creating a second fpext when there were multiple
uses.

llvm-svn: 292172

llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
index ec2ebaa..c68a5ca 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -1631,6 +1631,18 @@
       return SelectInst::Create(Cond, Call0, Call1);
     }
 
+    Value *ExtSrc;
+    if (match(II->getArgOperand(0), m_FPExt(m_Value(ExtSrc))) &&
+        II->getArgOperand(0)->hasOneUse()) {
+      // fabs (fpext x) -> fpext (fabs x)
+      Value *F = Intrinsic::getDeclaration(II->getModule(), Intrinsic::fabs,
+                                           { ExtSrc->getType() });
+      CallInst *NewFabs = Builder->CreateCall(F, ExtSrc);
+      NewFabs->copyFastMathFlags(II);
+      NewFabs->takeName(II);
+      return new FPExtInst(NewFabs, II->getType());
+    }
+
     break;
   }
   case Intrinsic::cos:

llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp
index e74b590..5ba6fd6 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp
@@ -1392,21 +1392,24 @@
   IntrinsicInst *II = dyn_cast<IntrinsicInst>(CI.getOperand(0));
   if (II) {
     switch (II->getIntrinsicID()) {
-      default: break;
-      case Intrinsic::fabs: {
-        // (fptrunc (fabs x)) -> (fabs (fptrunc x))
-        Value *InnerTrunc = Builder->CreateFPTrunc(II->getArgOperand(0),
-                                                   CI.getType());
-        Type *IntrinsicType[] = { CI.getType() };
-        Function *Overload = Intrinsic::getDeclaration(
-            CI.getModule(), II->getIntrinsicID(), IntrinsicType);
+    default: break;
+    case Intrinsic::fabs: {
+      // (fptrunc (fabs x)) -> (fabs (fptrunc x))
+      Value *InnerTrunc = Builder->CreateFPTrunc(II->getArgOperand(0),
+                                                 CI.getType());
+      Type *IntrinsicType[] = { CI.getType() };
+      Function *Overload = Intrinsic::getDeclaration(
+        CI.getModule(), II->getIntrinsicID(), IntrinsicType);
 
-        SmallVector<OperandBundleDef, 1> OpBundles;
-        II->getOperandBundlesAsDefs(OpBundles);
+      SmallVector<OperandBundleDef, 1> OpBundles;
+      II->getOperandBundlesAsDefs(OpBundles);
 
-        Value *Args[] = { InnerTrunc };
-        return CallInst::Create(Overload, Args, OpBundles, II->getName());
-      }
+      Value *Args[] = { InnerTrunc };
+      CallInst *NewCI =  CallInst::Create(Overload, Args,
+                                          OpBundles, II->getName());
+      NewCI->copyFastMathFlags(II);
+      return NewCI;
+    }
     }
   }
 

llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp

diff --git a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
index 8eaeb10..945814e 100644
--- a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -1210,11 +1210,15 @@
 
 Value *LibCallSimplifier::optimizeFabs(CallInst *CI, IRBuilder<> &B) {
   Function *Callee = CI->getCalledFunction();
-  StringRef Name = Callee->getName();
-  if (Name == "fabs" && hasFloatVersion(Name))
-    return optimizeUnaryDoubleFP(CI, B, false);
+  IRBuilder<>::FastMathFlagGuard Guard(B);
+  B.setFastMathFlags(CI->getFastMathFlags());
 
-  return nullptr;
+  // fabs/fabsf -> llvm.fabs.*
+  Value *F = Intrinsic::getDeclaration(Callee->getParent(), Intrinsic::fabs,
+                                       CI->getType());
+  Value *NewCall = B.CreateCall(F, { CI->getArgOperand(0) });
+  NewCall->takeName(CI);
+  return NewCall;
 }
 
 Value *LibCallSimplifier::optimizeFMinFMax(CallInst *CI, IRBuilder<> &B) {
@@ -2029,8 +2033,6 @@
       return optimizePow(CI, Builder);
     case Intrinsic::exp2:
       return optimizeExp2(CI, Builder);
-    case Intrinsic::fabs:
-      return optimizeFabs(CI, Builder);
     case Intrinsic::log:
       return optimizeLog(CI, Builder);
     case Intrinsic::sqrt: