Merging r258325:

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r258325 | spatel | 2016-01-20 09:41:14 -0800 (Wed, 20 Jan 2016) | 21 lines

[LibCallSimplifier] don't get fooled by a fake sqrt()

The test case will crash without this patch because the subsequent call to
hasUnsafeAlgebra() assumes that the call instruction is an FPMathOperator
(ie, returns an FP type).

This part of the function signature check was omitted for the sqrt() case,
but seems to be in place for all other transforms.

Before:
http://reviews.llvm.org/rL257400
...we would have needlessly continued execution in optimizeSqrt(), but the
bug was harmless because we'd eventually fail some other check and return
without damage.

This should fix:
https://llvm.org/bugs/show_bug.cgi?id=26211

Differential Revision: http://reviews.llvm.org/D16198

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_38@258353 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Utils/SimplifyLibCalls.cpp b/lib/Transforms/Utils/SimplifyLibCalls.cpp
index dc07440601423073c22eaf46f02ae652a2010b75..908b4bb6a654e99bb6ccdf4774873a93a9833d5f 100644 (file)
--- a/lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ b/lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -1394,12 +1394,21 @@ Value *LibCallSimplifier::optimizeLog(CallInst *CI, IRBuilder<> &B) {
 
 Value *LibCallSimplifier::optimizeSqrt(CallInst *CI, IRBuilder<> &B) {
   Function *Callee = CI->getCalledFunction();
-  
+
   Value *Ret = nullptr;
   if (TLI->has(LibFunc::sqrtf) && (Callee->getName() == "sqrt" ||
                                    Callee->getIntrinsicID() == Intrinsic::sqrt))
     Ret = optimizeUnaryDoubleFP(CI, B, true);
 
+  // FIXME: Refactor - this check is repeated all over this file and even in the
+  // preceding call to shrink double -> float.
+
+  // Make sure this has 1 argument of FP type, which matches the result type.
+  FunctionType *FT = Callee->getFunctionType();
+  if (FT->getNumParams() != 1 || FT->getReturnType() != FT->getParamType(0) ||
+      !FT->getParamType(0)->isFloatingPointTy())
+    return Ret;
+
   if (!CI->hasUnsafeAlgebra())
     return Ret;
 

diff --git a/test/Transforms/InstCombine/cos-2.ll b/test/Transforms/InstCombine/cos-2.ll
index c9a9c7c077123295784a450d7fb79b22508b5960..a85cc8fa6bde45fdf5899fa49bffdf659918ccd1 100644 (file)
--- a/test/Transforms/InstCombine/cos-2.ll
+++ b/test/Transforms/InstCombine/cos-2.ll
@@ -1,12 +1,11 @@
-; Test that the cos library call simplifier works correctly.
-;
 ; RUN: opt < %s -instcombine -S | FileCheck %s
 
 target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
 
 declare float @cos(double)
+declare signext i8 @sqrt(...)
 
-; Check that cos functions with the wrong prototype aren't simplified.
+; Check that functions with the wrong prototype aren't simplified.
 
 define float @test_no_simplify1(double %d) {
 ; CHECK-LABEL: @test_no_simplify1(
@@ -15,3 +14,14 @@ define float @test_no_simplify1(double %d) {
 ; CHECK: call float @cos(double %neg)
   ret float %cos
 }
+
+
+define i8 @bogus_sqrt() {
+  %fake_sqrt = call signext i8 (...) @sqrt()
+  ret i8 %fake_sqrt
+
+; CHECK-LABEL: bogus_sqrt(
+; CHECK-NEXT:  %fake_sqrt = call signext i8 (...) @sqrt()
+; CHECK-NEXT:  ret i8 %fake_sqrt
+}
+