q.bad.ll
7.19 KB
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; RUN: opt < %s -basic-aa -aa-eval -print-all-alias-modref-info -disable-output 2>&1 | FileCheck %s
target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
target triple = "thumbv7--linux-gnueabi"
; CHECK-LABEL: test_zext_sext_amounts255
; CHECK: NoAlias: i8* %a, i8* %b
define void @test_zext_sext_amounts255(i8* %mem) {
%sext.1 = sext i8 255 to i16
%sext.zext.1 = zext i16 %sext.1 to i64
%sext.2 = sext i8 255 to i32
%sext.zext.2 = zext i32 %sext.2 to i64
%a = getelementptr inbounds i8, i8* %mem, i64 %sext.zext.1
%b = getelementptr inbounds i8, i8* %mem, i64 %sext.zext.2
ret void
}
; CHECK-LABEL: test_zext_sext_amounts
; CHECK: MayAlias: i8* %a, i8* %b
; %a and %b only PartialAlias as, although they're both zext(sext(%num)) they'll extend the sign by a different
; number of bits before zext-ing the remainder.
define void @test_zext_sext_amounts(i8* %mem, i8 %num) {
%sext.1 = sext i8 %num to i16
%sext.zext.1 = zext i16 %sext.1 to i64
%sext.2 = sext i8 %num to i32
%sext.zext.2 = zext i32 %sext.2 to i64
%a = getelementptr inbounds i8, i8* %mem, i64 %sext.zext.1
%b = getelementptr inbounds i8, i8* %mem, i64 %sext.zext.2
ret void
}
; CHECK-LABEL: based_on_pr18068
; CHECK: NoAlias: i8* %a, i8* %b
; CHECK: NoAlias: i8* %a, i8* %c
define void @based_on_pr18068(i32 %loaded, i8* %mem) {
%loaded.64 = zext i32 %loaded to i64
%add1 = add i32 %loaded, -1 ; unsigned wraps unless %loaded == 0
%add1.64 = zext i32 %add1 to i64 ; is zext(%loaded) always != zext(%loaded - 1)? Yes -> NoAlias
%sub1 = sub i32 %loaded, 1 ; unsigned wraps iff %loaded == 0
%sub1.64 = zext i32 %sub1 to i64 ; is zext(%loaded) always != zext(%loaded - 1)? Yes -> NoAlias
%a = getelementptr inbounds i8, i8* %mem, i64 %loaded.64
%b = getelementptr inbounds i8, i8* %mem, i64 %add1.64
%c = getelementptr inbounds i8, i8* %mem, i64 %sub1.64
ret void
}
; CHECK-LABEL: test_path_dependence
; CHECK: MayAlias: i8* %a, i8* %b
; CHECK: MustAlias: i8* %a, i8* %c
; CHECK: MayAlias: i8* %a, i8* %d
define void @test_path_dependence(i32 %p, i8* %mem) {
%p.minus1 = add i32 %p, -1 ; this will always unsigned-wrap, unless %p == 0
%p.minus1.64 = zext i32 %p.minus1 to i64
%p.64.again = add i64 %p.minus1.64, 1 ; either %p (if we wrapped) or 4294967296 (if we didn't)
%p.nsw.nuw.minus1 = sub nsw nuw i32 %p, 1 ; as nuw we know %p >= 1, and as nsw %p <= 2147483647
%p.nsw.nuw.minus1.64 = zext i32 %p.nsw.nuw.minus1 to i64
%p.nsw.nuw.64.again = add nsw nuw i64 %p.nsw.nuw.minus1.64, 1 ; ...so always exactly %p
%p.nsw.minus1 = sub nsw i32 %p, 1 ; only nsw, so can only guarantee %p != 0x10000000
%p.nsw.minus1.64 = zext i32 %p.nsw.minus1 to i64 ; when %p > 0x10000000 (ie <= 0 as a signed number) then the zext will make this a huge positive number
%p.nsw.64.again = add nsw i64 %p.nsw.minus1.64, 1 ; ...and so this is very much != %p
%p.64 = zext i32 %p to i64
%a = getelementptr inbounds i8, i8* %mem, i64 %p.64
%b = getelementptr inbounds i8, i8* %mem, i64 %p.64.again
%c = getelementptr inbounds i8, i8* %mem, i64 %p.nsw.nuw.64.again
%d = getelementptr inbounds i8, i8* %mem, i64 %p.nsw.64.again
ret void
}
; CHECK-LABEL: test_zext_sext_255
; CHECK: NoAlias: i8* %a, i8* %b
define void @test_zext_sext_255(i8* %mem) {
%zext.255 = zext i8 255 to i16 ; 0x00FF
%sext.255 = sext i8 255 to i16 ; 0xFFFF
%zext.sext.255 = zext i16 %sext.255 to i32 ; 0x0000FFFF
%sext.zext.255 = sext i16 %zext.255 to i32 ; 0x000000FF
%zext.zext.sext.255 = zext i32 %zext.sext.255 to i64
%zext.sext.zext.255 = zext i32 %sext.zext.255 to i64
%a = getelementptr inbounds i8, i8* %mem, i64 %zext.zext.sext.255
%b = getelementptr inbounds i8, i8* %mem, i64 %zext.sext.zext.255
ret void
}
; CHECK-LABEL: test_zext_sext_num
; CHECK: MayAlias: i8* %a, i8* %b
; %a and %b NoAlias if %num == 255 (see @test_zext_sext_255), but %a and %b NoAlias for other values of %num (e.g. 0)
define void @test_zext_sext_num(i8* %mem, i8 %num) {
%zext.num = zext i8 %num to i16
%sext.num = sext i8 %num to i16
%zext.sext.num = zext i16 %sext.num to i32
%sext.zext.num = sext i16 %zext.num to i32
%zext.zext.sext.num = zext i32 %zext.sext.num to i64
%zext.sext.zext.num = zext i32 %sext.zext.num to i64
%a = getelementptr inbounds i8, i8* %mem, i64 %zext.zext.sext.num
%b = getelementptr inbounds i8, i8* %mem, i64 %zext.sext.zext.num
ret void
}
; CHECK-LABEL: uncompressStream
; CHECK: MustAlias: i8* %a, i8* %b
; CHECK: NoAlias: i8* %a, i8* %c
define void @uncompressStream(i8* %mem) {
%zext.255 = zext i8 255 to i32
%sext.255 = sext i8 255 to i32
%a = getelementptr inbounds i8, i8* %mem, i32 255
%b = getelementptr inbounds i8, i8* %mem, i32 %zext.255
%c = getelementptr inbounds i8, i8* %mem, i32 %sext.255
ret void
}
; CHECK-LABEL: constantOffsetHeuristic_i3_i32
; CHECK: NoAlias: i32* %a, i32* %b
; CHECK: NoAlias: i32* %a, i32* %c
; CHECK: NoAlias: i32* %b, i32* %c
define void @constantOffsetHeuristic_i3_i32(i32* %mem, i3 %val) {
%zext.plus.7 = add nsw i3 %val, 7
%zext.plus.4 = add nsw i3 %val, 4
%zext.val = zext i3 %val to i32
%zext.4 = zext i3 %zext.plus.4 to i32
%zext.7 = zext i3 %zext.plus.7 to i32
%a = getelementptr inbounds i32, i32* %mem, i32 %zext.4
%b = getelementptr inbounds i32, i32* %mem, i32 %zext.7
%c = getelementptr inbounds i32, i32* %mem, i32 %zext.val
ret void
}
; CHECK-LABEL: constantOffsetHeuristic_i8_i32
; CHECK: NoAlias: i32* %a, i32* %b
; CHECK: NoAlias: i32* %a, i32* %c
; CHECK: NoAlias: i32* %b, i32* %c
define void @constantOffsetHeuristic_i8_i32(i32* %mem, i8 %val) {
%zext.plus.7 = add nsw i8 %val, 7
%zext.plus.4 = add nsw i8 %val, 4
%zext.val = zext i8 %val to i32
%zext.4 = zext i8 %zext.plus.4 to i32
%zext.7 = zext i8 %zext.plus.7 to i32
%a = getelementptr inbounds i32, i32* %mem, i32 %zext.4
%b = getelementptr inbounds i32, i32* %mem, i32 %zext.7
%c = getelementptr inbounds i32, i32* %mem, i32 %zext.val
ret void
}
; CHECK-LABEL: constantOffsetHeuristic_i3_i8
; CHECK: MayAlias: i32* %a, i32* %b
; CHECK: NoAlias: i32* %a, i32* %c
; CHECK: MayAlias: i32* %b, i32* %c
define void @constantOffsetHeuristic_i3_i8(i8* %mem, i3 %val) {
%zext.plus.7 = add nsw i3 %val, 7
%zext.plus.4 = add nsw i3 %val, 4
%zext.val = zext i3 %val to i32
%zext.4 = zext i3 %zext.plus.4 to i32
%zext.7 = zext i3 %zext.plus.7 to i32
%a.8 = getelementptr inbounds i8, i8* %mem, i32 %zext.4
%b.8 = getelementptr inbounds i8, i8* %mem, i32 %zext.7
%c.8 = getelementptr inbounds i8, i8* %mem, i32 %zext.val
%a = bitcast i8* %a.8 to i32*
%b = bitcast i8* %b.8 to i32*
%c = bitcast i8* %c.8 to i32*
ret void
}
; CHECK-LABEL: constantOffsetHeuristic_i8_i8
; CHECK: MayAlias: i32* %a, i32* %b
; CHECK: NoAlias: i32* %a, i32* %c
; CHECK: NoAlias: i32* %b, i32* %c
define void @constantOffsetHeuristic_i8_i8(i8* %mem, i8 %val) {
%zext.plus.7 = add nsw i8 %val, 7
%zext.plus.4 = add nsw i8 %val, 4
%zext.val = zext i8 %val to i32
%zext.4 = zext i8 %zext.plus.4 to i32
%zext.7 = zext i8 %zext.plus.7 to i32
%a.8 = getelementptr inbounds i8, i8* %mem, i32 %zext.4
%b.8 = getelementptr inbounds i8, i8* %mem, i32 %zext.7
%c.8 = getelementptr inbounds i8, i8* %mem, i32 %zext.val
%a = bitcast i8* %a.8 to i32*
%b = bitcast i8* %b.8 to i32*
%c = bitcast i8* %c.8 to i32*
ret void
}