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Fix a bug in just submitted rL369789

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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
This commit is contained in:
Philip Reames 2019-08-23 18:27:57 +00:00
parent 2fd1afe8ef
commit 9cb059fdcc
2 changed files with 30 additions and 1 deletions
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5
llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
View File

@ -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.

26
llvm/test/Transforms/InstCombine/gep-inbounds-null.ll
View File

@ -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) {