From: Philip Reames <listmail@philipreames.com>
Date: Fri, 23 Aug 2019 18:27:57 +0000 (+0000)
Subject: Fix a bug in just submitted rL369789
X-Git-Tag: llvmorg-11-init~10988
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=9cb059fdcc03e2144fa9aac0bfbb49c0d5d7efe2;p=platform%2Fupstream%2Fllvm.git

Fix a bug in just submitted rL369789

Started implementing the vector case and realized the scalar case hadn't handled the GEP producing a different type than the base correctly.  It's entertaining seeing what slips through review when we're focused on the 'hard' parts.  :(

Also adding an extra vector test as it happened to be in workspace and wasn't worth separating.

llvm-svn: 369795
---

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
index 2bc21292b137..4e161d612cfe 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -914,7 +914,10 @@ Instruction *InstCombiner::foldGEPICmp(GEPOperator *GEPLHS, Value *RHS,
     // In general, we're allowed to make values less poison (i.e. remove
     //   sources of full UB), so in this case, we just select between the two
     //   non-poison cases (1 and 4 above).
-    return new ICmpInst(Cond, GEPLHS->getPointerOperand(), RHS);
+    auto *Base = GEPLHS->getPointerOperand();
+    return new ICmpInst(Cond, Base,
+                        ConstantExpr::getBitCast(cast<Constant>(RHS),
+                                                 Base->getType()));
   } else if (GEPOperator *GEPRHS = dyn_cast<GEPOperator>(RHS)) {
     // If the base pointers are different, but the indices are the same, just
     // compare the base pointer.
diff --git a/llvm/test/Transforms/InstCombine/gep-inbounds-null.ll b/llvm/test/Transforms/InstCombine/gep-inbounds-null.ll
index c369c1e513bc..544f9a3f2e38 100644
--- a/llvm/test/Transforms/InstCombine/gep-inbounds-null.ll
+++ b/llvm/test/Transforms/InstCombine/gep-inbounds-null.ll
@@ -102,6 +102,19 @@ entry:
   ret <2 x i1> %cnd
 }
 
+define <2 x i1> @test_vector_both(<2 x i8*> %base, <2 x i64> %idx) {
+; CHECK-LABEL: @test_vector_both(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[GEP:%.*]] = getelementptr inbounds i8, <2 x i8*> [[BASE:%.*]], <2 x i64> [[IDX:%.*]]
+; CHECK-NEXT:    [[CND:%.*]] = icmp eq <2 x i8*> [[GEP]], zeroinitializer
+; CHECK-NEXT:    ret <2 x i1> [[CND]]
+;
+entry:
+  %gep = getelementptr inbounds i8, <2 x i8*> %base, <2 x i64> %idx
+  %cnd = icmp eq <2 x i8*> %gep, zeroinitializer
+  ret <2 x i1> %cnd
+}
+
 ;; These two show instsimplify's reasoning getting to the non-zero offsets
 ;; before instcombine does.
 
@@ -155,6 +168,19 @@ entry:
 }
 
 
+define i1 @test_index_type([10 x i8]* %base, i64 %idx) {
+; CHECK-LABEL: @test_index_type(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[CND:%.*]] = icmp eq [10 x i8]* [[BASE:%.*]], null
+; CHECK-NEXT:    ret i1 [[CND]]
+;
+entry:
+  %gep = getelementptr inbounds [10 x i8], [10 x i8]* %base, i64 %idx, i64 %idx
+  %cnd = icmp eq i8* %gep, null
+  ret i1 %cnd
+}
+
+
 ;; Finally, some negative tests for sanity checking.
 
 define i1 @neq_noinbounds(i8* %base, i64 %idx) {