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llvm-mirror/test/Transforms/InstCombine/out-of-bounds-indexes.ll
Nikita Popov f1a3e21dd2 [InstSimplify] Fold out-of-bounds shift to poison
Make InstSimplify return poison rather than undef for out-of-bounds
shifts, as specified by LandRef:

> If op2 is (statically or dynamically) equal to or larger than the
> number of bits in op1, this instruction returns a poison value.

Differential Revision: https://reviews.llvm.org/D93998
2021-01-06 20:41:37 +01:00

42 lines
1.2 KiB
LLVM

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -S -instcombine < %s | FileCheck %s
; Check that we don't crash on unreasonable constant indexes
define i32 @test_out_of_bounds(i32 %a, i1 %x, i1 %y) {
; CHECK-LABEL: @test_out_of_bounds(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[AND1:%.*]] = and i32 [[A:%.*]], 3
; CHECK-NEXT: tail call void @llvm.assume(i1 poison)
; CHECK-NEXT: ret i32 [[AND1]]
;
entry:
%and1 = and i32 %a, 3
%B = lshr i32 %and1, -2147483648
%cmp = icmp eq i32 %B, 1
tail call void @llvm.assume(i1 %cmp)
ret i32 %and1
}
define i128 @test_non64bit(i128 %a) {
; CHECK-LABEL: @test_non64bit(
; CHECK-NEXT: [[AND1:%.*]] = and i128 [[A:%.*]], 3
; CHECK-NEXT: tail call void @llvm.assume(i1 poison)
; CHECK-NEXT: ret i128 [[AND1]]
;
%and1 = and i128 %a, 3
%B = lshr i128 %and1, -1
%cmp = icmp eq i128 %B, 1
tail call void @llvm.assume(i1 %cmp)
ret i128 %and1
}
declare void @llvm.assume(i1)
define <4 x double> @inselt_bad_index(<4 x double> %a) {
; CHECK-LABEL: @inselt_bad_index(
; CHECK-NEXT: ret <4 x double> poison
;
%I = insertelement <4 x double> %a, double 0.0, i64 4294967296
ret <4 x double> %I
}