[PartialInlineLibCalls] Teach PartialInlineLibCalls to honor nobuiltin, properly check the function signature, and check TLI::has

Summary:
We shouldn't do this transformation if the function is marked nobuitlin.

We were only checking that the return type is floating point, we really should be checking the argument types and argument count as well. This can be accomplished by using the other version of getLibFunc that takes the Function and not just the name.

We should also be checking TLI::has since sqrtf is a macro on Windows.

Fixes PR32559.

Reviewers: hfinkel, spatel, davide, efriedma

Reviewed By: davide, efriedma

Subscribers: efriedma, llvm-commits, eraman

Differential Revision: https://reviews.llvm.org/D39381

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@316819 91177308-0d34-0410-b5e6-96231b3b80d8

Author: topperc

lib/Transforms/Scalar/PartiallyInlineLibCalls.cpp

@@ -32,10 +32,6 @@ static bool optimizeSQRT(CallInst *Call, Function *CalledFunc,
   if (Call->onlyReadsMemory())
     return false;
 
-  // The call must have the expected result type.
-  if (!Call->getType()->isFloatingPointTy())
-    return false;
-
   // Do the following transformation:
   //
   // (before)
@@ -96,11 +92,14 @@ static bool runPartiallyInlineLibCalls(Function &F, TargetLibraryInfo *TLI,
       if (!Call || !(CalledFunc = Call->getCalledFunction()))
         continue;
 
+      if (Call->isNoBuiltin())
+        continue;
+
       // Skip if function either has local linkage or is not a known library
       // function.
       LibFunc LF;
-      if (CalledFunc->hasLocalLinkage() || !CalledFunc->hasName() ||
-          !TLI->getLibFunc(CalledFunc->getName(), LF))
+      if (CalledFunc->hasLocalLinkage() ||
+          !TLI->getLibFunc(*CalledFunc, LF) || !TLI->has(LF))
         continue;
 
       switch (LF) {

test/Transforms/PartiallyInlineLibCalls/bad-prototype.ll

@@ -4,6 +4,7 @@
 target triple = "x86_64-unknown-linux-gnu"
 
 declare i32 @sqrt()
+declare float @sqrtf()
 
 ; CHECK-LABEL: @foo
 define i32 @foo() {
@@ -12,3 +13,11 @@ define i32 @foo() {
   %r = call i32 @sqrt()
   ret i32 %r
 }
+
+; CHECK-LABEL: @bar
+define float @bar() {
+  ; CHECK: call{{.*}}@sqrtf
+  ; CHECK-NOT: call{{.*}}@sqrtf
+  %r = call float @sqrtf()
+  ret float %r
+}

test/Transforms/PartiallyInlineLibCalls/nobuiltin.ll

@@ -0,0 +1,12 @@
+; RUN: opt -S -partially-inline-libcalls -mtriple=x86_64-unknown-linux-gnu < %s | FileCheck %s
+; RUN: opt -S -passes=partially-inline-libcalls -mtriple=x86_64-unknown-linux-gnu < %s | FileCheck %s
+
+define float @f(float %val) {
+; CHECK-LABEL: @f
+; CHECK: call{{.*}}@sqrtf
+; CHECK-NOT: call{{.*}}@sqrtf
+  %res = tail call float @sqrtf(float %val) nobuiltin
+  ret float %res
+}
+
+declare float @sqrtf(float)