3c9f3f76f1
With opaque pointers, we can eliminate zero-index GEPs even if they have multiple indices, as this no longer impacts the result type of the GEP. This optimization is already done for instructions in InstSimplify, but we were missing the corresponding constant expression handling. The constexpr transform is a bit more powerful, because it can produce a vector splat constant and also handles undef values -- it is an extension of an existing single-index transform.
43 lines
1.5 KiB
LLVM
43 lines
1.5 KiB
LLVM
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
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; RUN: opt -S -indvars -opaque-pointers < %s | FileCheck %s
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target datalayout = "n8:16:32:64"
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@data = common global [240 x i8] zeroinitializer, align 16
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; Based on the test from lftr.ll
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define void @test_zext(ptr %a) {
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; CHECK-LABEL: @test_zext(
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; CHECK-NEXT: entry:
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; CHECK-NEXT: br label [[LOOP:%.*]]
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; CHECK: loop:
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; CHECK-NEXT: [[P_0:%.*]] = phi ptr [ @data, [[ENTRY:%.*]] ], [ [[T3:%.*]], [[LOOP]] ]
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; CHECK-NEXT: [[DOT0:%.*]] = phi ptr [ [[A:%.*]], [[ENTRY]] ], [ [[T:%.*]], [[LOOP]] ]
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; CHECK-NEXT: [[T]] = getelementptr inbounds i8, ptr [[DOT0]], i64 1
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; CHECK-NEXT: [[T2:%.*]] = load i8, ptr [[DOT0]], align 1
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; CHECK-NEXT: [[T3]] = getelementptr inbounds i8, ptr [[P_0]], i64 1
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; CHECK-NEXT: store i8 [[T2]], ptr [[P_0]], align 1
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; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne ptr [[P_0]], getelementptr (i8, ptr @data, i64 239)
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; CHECK-NEXT: br i1 [[EXITCOND]], label [[LOOP]], label [[EXIT:%.*]]
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; CHECK: exit:
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; CHECK-NEXT: ret void
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;
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entry:
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br label %loop
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loop:
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%i.0 = phi i8 [ 0, %entry ], [ %t4, %loop ]
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%p.0 = phi ptr [ getelementptr inbounds ([240 x i8], [240 x i8]* @data, i64 0, i64 0), %entry ], [ %t3, %loop ]
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%.0 = phi ptr [ %a, %entry ], [ %t, %loop ]
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%t = getelementptr inbounds i8, ptr %.0, i64 1
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%t2 = load i8, ptr %.0, align 1
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%t3 = getelementptr inbounds i8, ptr %p.0, i64 1
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store i8 %t2, ptr %p.0, align 1
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%t4 = add i8 %i.0, 1
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%t5 = icmp ult i8 %t4, -16
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br i1 %t5, label %loop, label %exit
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exit:
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ret void
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}
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