commit f79d8a064ce4d8846377e4abbc9a389b62f90d43
author Craig Topper <craig.topper@intel.com> Wed Aug 28 15:40:34 2019 +0000
committer Craig Topper <craig.topper@intel.com> Wed Aug 28 15:40:34 2019 +0000
tree bfe6f428710e7825d3b804fe31fae7ac2f3a1ff1
parent b569624049311a6975495a82abc9fa78d4548c44

[InstCombine] Disable recursion in foldGEPICmp for vector pointer GEPs

Due to missing vector support in this function, recursion can
generate worse code in some cases.

llvm-svn: 370221

llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
index dad38e38..3a01d9c 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -988,12 +988,14 @@
     }
 
     // If one of the GEPs has all zero indices, recurse.
-    if (GEPLHS->hasAllZeroIndices())
+    // FIXME: Handle vector of pointers.
+    if (!GEPLHS->getType()->isVectorTy() && GEPLHS->hasAllZeroIndices())
       return foldGEPICmp(GEPRHS, GEPLHS->getOperand(0),
                          ICmpInst::getSwappedPredicate(Cond), I);
 
     // If the other GEP has all zero indices, recurse.
-    if (GEPRHS->hasAllZeroIndices())
+    // FIXME: Handle vector of pointers.
+    if (!GEPRHS->getType()->isVectorTy() && GEPRHS->hasAllZeroIndices())
       return foldGEPICmp(GEPLHS, GEPRHS->getOperand(0), Cond, I);
 
     bool GEPsInBounds = GEPLHS->isInBounds() && GEPRHS->isInBounds();

llvm/test/Transforms/InstCombine/gep-custom-dl.ll

diff --git a/llvm/test/Transforms/InstCombine/gep-custom-dl.ll b/llvm/test/Transforms/InstCombine/gep-custom-dl.ll
index e226530..ac47d93 100644
--- a/llvm/test/Transforms/InstCombine/gep-custom-dl.ll
+++ b/llvm/test/Transforms/InstCombine/gep-custom-dl.ll
@@ -110,6 +110,18 @@
   ret <2 x i1> %C
 }
 
+; Same as above, but indices scalarized.
+define <2 x i1> @test6b(<2 x i32> %X, <2 x %S*> %P) nounwind {
+; CHECK-LABEL: @test6b(
+; CHECK-NEXT:    [[C:%.*]] = icmp eq <2 x i32> [[X:%.*]], <i32 1073741823, i32 1073741823>
+; CHECK-NEXT:    ret <2 x i1> [[C]]
+;
+  %A = getelementptr inbounds %S, <2 x %S*> %P, i32 0, i32 1, <2 x i32> %X
+  %B = getelementptr inbounds %S, <2 x %S*> %P, i32 0, i32 0
+  %C = icmp eq <2 x i32*> %A, %B
+  ret <2 x i1> %C
+}
+
 @G = external global [3 x i8]
 define i8* @test7(i16 %Idx) {
 ; CHECK-LABEL: @test7(