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[LowerConstantIntrinsics] Improve tests related to llvm.objectsize. NFC #132364

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fb76d24
[LowerConstantIntrinsics] Improve tests related to llvm.objectsize. NFC
bjope Mar 18, 2025
26d92c3
Update new lit test to run a single pass.
bjope Mar 26, 2025
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256 changes: 256 additions & 0 deletions llvm/test/Transforms/LowerConstantIntrinsics/builtin-object-size-idxsize.ll
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@@ -0,0 +1,256 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
; RUN: opt -passes='sroa,instcombine,lower-constant-intrinsics,dce' -S < %s | FileCheck --check-prefixes CHECK,CHECK-REF %s
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Could we achieve the same test coverage without relying on other passes?

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Yes. Using a different pipleine as a REF was useful when trying to find situations when the behavior diverged when running lower-constant-intrinsics standalone. But that should not be needed for the final regression test. I agree that it is better to just use a single pass test.

; RUN: opt -passes=lower-constant-intrinsics,dce -S < %s | FileCheck --check-prefixes CHECK,CHECK-TST %s

; Some extra tests using 16-bit pointers and 16-bit index type size. This
; allows us to for example test what happens when the index type used in a
; getelementptr does not match with the index type size (e.g. when not running
; full opt pipeline before the lower-constant-intrinsics pass).

target datalayout = "e-p:16:16:16"


define i32 @possible_out_of_bounds_gep_i8(i1 %c0, i1 %c1) {
; CHECK-LABEL: define i32 @possible_out_of_bounds_gep_i8(
; CHECK-SAME: i1 [[C0:%.*]], i1 [[C1:%.*]]) {
; CHECK-NEXT: [[ENTRY:.*:]]
; CHECK-NEXT: [[RES:%.*]] = select i1 [[C1]], i32 3, i32 0
; CHECK-NEXT: ret i32 [[RES]]
;
entry:
%obj = alloca [5 x i8]
%offset = select i1 %c0, i8 2, i8 10
%ptr.slide = getelementptr i8, ptr %obj, i8 %offset
%objsize_max = call i32 @llvm.objectsize.i32.p0(ptr %ptr.slide, i1 false, i1 true, i1 false)
%objsize_min = call i32 @llvm.objectsize.i32.p0(ptr %ptr.slide, i1 true, i1 true, i1 false)
%res = select i1 %c1, i32 %objsize_max, i32 %objsize_min
ret i32 %res
}

define i32 @possible_out_of_bounds_gep_i16(i1 %c0, i1 %c1) {
; CHECK-LABEL: define i32 @possible_out_of_bounds_gep_i16(
; CHECK-SAME: i1 [[C0:%.*]], i1 [[C1:%.*]]) {
; CHECK-NEXT: [[ENTRY:.*:]]
; CHECK-NEXT: [[RES:%.*]] = select i1 [[C1]], i32 3, i32 0
; CHECK-NEXT: ret i32 [[RES]]
;
entry:
%obj = alloca [5 x i8]
%offset = select i1 %c0, i16 2, i16 10
%ptr.slide = getelementptr i8, ptr %obj, i16 %offset
%objsize_max = call i32 @llvm.objectsize.i32.p0(ptr %ptr.slide, i1 false, i1 true, i1 false)
%objsize_min = call i32 @llvm.objectsize.i32.p0(ptr %ptr.slide, i1 true, i1 true, i1 false)
%res = select i1 %c1, i32 %objsize_max, i32 %objsize_min
ret i32 %res
}

define i32 @possible_out_of_bounds_gep_i32(i1 %c0, i1 %c1) {
; CHECK-LABEL: define i32 @possible_out_of_bounds_gep_i32(
; CHECK-SAME: i1 [[C0:%.*]], i1 [[C1:%.*]]) {
; CHECK-NEXT: [[ENTRY:.*:]]
; CHECK-NEXT: [[RES:%.*]] = select i1 [[C1]], i32 3, i32 0
; CHECK-NEXT: ret i32 [[RES]]
;
entry:
%obj = alloca [5 x i8]
%offset = select i1 %c0, i32 2, i32 10
%ptr.slide = getelementptr i8, ptr %obj, i32 %offset
%objsize_max = call i32 @llvm.objectsize.i32.p0(ptr %ptr.slide, i1 false, i1 true, i1 false)
%objsize_min = call i32 @llvm.objectsize.i32.p0(ptr %ptr.slide, i1 true, i1 true, i1 false)
%res = select i1 %c1, i32 %objsize_max, i32 %objsize_min
ret i32 %res
}

; SROA would produce IR like this if applied to @possible_out_of_bounds_gep_i16.
; FIXME: The %objsize_min result here looks wrong.
define i32 @possible_out_of_bounds_gep_i16_sroa(i1 %c0, i1 %c1) {
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instead of having two check prefixes, I'd rather have two different functions and one check, one of which would just hard-code the output of sroa

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This is the alternative IR with the output of sroa.
(I've now removed the the alternative RUN line that I used as a reference. So I hope this makes more sense now.)

; CHECK-REF-LABEL: define i32 @possible_out_of_bounds_gep_i16_sroa(
; CHECK-REF-SAME: i1 [[C0:%.*]], i1 [[C1:%.*]]) {
; CHECK-REF-NEXT: [[ENTRY:.*:]]
; CHECK-REF-NEXT: [[RES:%.*]] = select i1 [[C1]], i32 3, i32 0
; CHECK-REF-NEXT: ret i32 [[RES]]
;
; CHECK-TST-LABEL: define i32 @possible_out_of_bounds_gep_i16_sroa(
; CHECK-TST-SAME: i1 [[C0:%.*]], i1 [[C1:%.*]]) {
; CHECK-TST-NEXT: [[ENTRY:.*:]]
; CHECK-TST-NEXT: [[RES:%.*]] = select i1 [[C1]], i32 3, i32 65531
; CHECK-TST-NEXT: ret i32 [[RES]]
;
entry:
%obj = alloca [5 x i8], align 1
%.sroa.gep = getelementptr i8, ptr %obj, i16 2
%.sroa.gep1 = getelementptr i8, ptr %obj, i16 10
%offset.sroa.sel = select i1 %c0, ptr %.sroa.gep, ptr %.sroa.gep1
%objsize_max = call i32 @llvm.objectsize.i32.p0(ptr %offset.sroa.sel, i1 false, i1 true, i1 false)
%objsize_min = call i32 @llvm.objectsize.i32.p0(ptr %offset.sroa.sel, i1 true, i1 true, i1 false)
%res = select i1 %c1, i32 %objsize_max, i32 %objsize_min
ret i32 %res
}

; Indices are truncated to the pointer size in a gep. So "i32 -65526" should
; be truncated to "i16 10".
; FIXME: The TST result here is incorrect!
define i32 @possible_out_of_bounds_gep_i32_trunc(i1 %c0, i1 %c1) {
; CHECK-REF-LABEL: define i32 @possible_out_of_bounds_gep_i32_trunc(
; CHECK-REF-SAME: i1 [[C0:%.*]], i1 [[C1:%.*]]) {
; CHECK-REF-NEXT: [[ENTRY:.*:]]
; CHECK-REF-NEXT: [[RES:%.*]] = select i1 [[C1]], i32 3, i32 0
; CHECK-REF-NEXT: ret i32 [[RES]]
;
; CHECK-TST-LABEL: define i32 @possible_out_of_bounds_gep_i32_trunc(
; CHECK-TST-SAME: i1 [[C0:%.*]], i1 [[C1:%.*]]) {
; CHECK-TST-NEXT: [[ENTRY:.*:]]
; CHECK-TST-NEXT: [[RES:%.*]] = select i1 [[C1]], i32 0, i32 3
; CHECK-TST-NEXT: ret i32 [[RES]]
;
entry:
%obj = alloca [5 x i8]
%offset = select i1 %c0, i32 2, i32 -65526 ; 0xffff000a
%ptr.slide = getelementptr i8, ptr %obj, i32 %offset
%objsize_max = call i32 @llvm.objectsize.i32.p0(ptr %ptr.slide, i1 false, i1 true, i1 false)
%objsize_min = call i32 @llvm.objectsize.i32.p0(ptr %ptr.slide, i1 true, i1 true, i1 false)
%res = select i1 %c1, i32 %objsize_max, i32 %objsize_min
ret i32 %res
}

define i32 @out_of_bounds_gep_i8(i1 %c0, i1 %c1) {
; CHECK-REF-LABEL: define i32 @out_of_bounds_gep_i8(
; CHECK-REF-SAME: i1 [[C0:%.*]], i1 [[C1:%.*]]) {
; CHECK-REF-NEXT: [[ENTRY:.*:]]
; CHECK-REF-NEXT: [[RES:%.*]] = sext i1 [[C1]] to i32
; CHECK-REF-NEXT: ret i32 [[RES]]
;
; CHECK-TST-LABEL: define i32 @out_of_bounds_gep_i8(
; CHECK-TST-SAME: i1 [[C0:%.*]], i1 [[C1:%.*]]) {
; CHECK-TST-NEXT: [[ENTRY:.*:]]
; CHECK-TST-NEXT: [[RES:%.*]] = select i1 [[C1]], i32 -1, i32 0
; CHECK-TST-NEXT: ret i32 [[RES]]
;
entry:
%obj = alloca [5 x i8]
%ptr.slide = getelementptr i8, ptr %obj, i8 -128
%objsize_max = call i32 @llvm.objectsize.i32.p0(ptr %ptr.slide, i1 false, i1 true, i1 false)
%objsize_min = call i32 @llvm.objectsize.i32.p0(ptr %ptr.slide, i1 true, i1 true, i1 false)
%res = select i1 %c1, i32 %objsize_max, i32 %objsize_min
ret i32 %res
}

define i32 @out_of_bounds_gep_i32(i1 %c0, i1 %c1) {
; CHECK-LABEL: define i32 @out_of_bounds_gep_i32(
; CHECK-SAME: i1 [[C0:%.*]], i1 [[C1:%.*]]) {
; CHECK-NEXT: [[ENTRY:.*:]]
; CHECK-NEXT: ret i32 0
;
entry:
%obj = alloca [5 x i8]
%ptr.slide = getelementptr i8, ptr %obj, i32 10
%objsize_max = call i32 @llvm.objectsize.i32.p0(ptr %ptr.slide, i1 false, i1 true, i1 false)
%objsize_min = call i32 @llvm.objectsize.i32.p0(ptr %ptr.slide, i1 true, i1 true, i1 false)
%res = select i1 %c1, i32 %objsize_max, i32 %objsize_min
ret i32 %res
}

define i32 @out_of_bounds_gep_i32_trunc(i1 %c0, i1 %c1) {
; CHECK-LABEL: define i32 @out_of_bounds_gep_i32_trunc(
; CHECK-SAME: i1 [[C0:%.*]], i1 [[C1:%.*]]) {
; CHECK-NEXT: [[ENTRY:.*:]]
; CHECK-NEXT: ret i32 0
;
entry:
%obj = alloca [5 x i8]
%ptr.slide = getelementptr i8, ptr %obj, i32 -65526
%objsize_max = call i32 @llvm.objectsize.i32.p0(ptr %ptr.slide, i1 false, i1 true, i1 false)
%objsize_min = call i32 @llvm.objectsize.i32.p0(ptr %ptr.slide, i1 true, i1 true, i1 false)
%res = select i1 %c1, i32 %objsize_max, i32 %objsize_min
ret i32 %res
}

; In this test the index will be out-of-bounds, but the current analysis won't
; detect that. The analysis will find out that %offset is in the range [-2,
; 10] which includes valid offsets that aren't out-of-bounds. Therefore we can
; expect the result -1 for %objsize_max.
define i32 @out_of_bounds_gep_i16_pos_neg(i1 %c0, i1 %c1) {
; CHECK-REF-LABEL: define i32 @out_of_bounds_gep_i16_pos_neg(
; CHECK-REF-SAME: i1 [[C0:%.*]], i1 [[C1:%.*]]) {
; CHECK-REF-NEXT: [[ENTRY:.*:]]
; CHECK-REF-NEXT: [[RES:%.*]] = sext i1 [[C1]] to i32
; CHECK-REF-NEXT: ret i32 [[RES]]
;
; CHECK-TST-LABEL: define i32 @out_of_bounds_gep_i16_pos_neg(
; CHECK-TST-SAME: i1 [[C0:%.*]], i1 [[C1:%.*]]) {
; CHECK-TST-NEXT: [[ENTRY:.*:]]
; CHECK-TST-NEXT: [[RES:%.*]] = select i1 [[C1]], i32 -1, i32 0
; CHECK-TST-NEXT: ret i32 [[RES]]
;
entry:
%obj = alloca [5 x i8]
%offset = select i1 %c0, i32 10, i32 -2
%ptr.slide = getelementptr i8, ptr %obj, i32 %offset
%objsize_max = call i32 @llvm.objectsize.i32.p0(ptr %ptr.slide, i1 false, i1 true, i1 false)
%objsize_min = call i32 @llvm.objectsize.i32.p0(ptr %ptr.slide, i1 true, i1 true, i1 false)
%res = select i1 %c1, i32 %objsize_max, i32 %objsize_min
ret i32 %res
}

; With 16-bit index size %offset is either 32767 or -32768. Thus, when
; aggregating the possible offsets it we know that it is in the range [-32768,
; 32767], which includes valid offsets that aren't out-of-bounds. This is
; similar to the out_of_bounds_gep_i16_pos_neg test above, and we can expect
; the result -1 for %objsize_max.
define i32 @out_of_bounds_gep_i32_trunc_select(i1 %c0, i1 %c1) {
; CHECK-REF-LABEL: define i32 @out_of_bounds_gep_i32_trunc_select(
; CHECK-REF-SAME: i1 [[C0:%.*]], i1 [[C1:%.*]]) {
; CHECK-REF-NEXT: [[ENTRY:.*:]]
; CHECK-REF-NEXT: [[RES:%.*]] = sext i1 [[C1]] to i32
; CHECK-REF-NEXT: ret i32 [[RES]]
;
; CHECK-TST-LABEL: define i32 @out_of_bounds_gep_i32_trunc_select(
; CHECK-TST-SAME: i1 [[C0:%.*]], i1 [[C1:%.*]]) {
; CHECK-TST-NEXT: [[ENTRY:.*:]]
; CHECK-TST-NEXT: ret i32 0
;
entry:
%obj = alloca [5 x i8]
%offset = select i1 %c0, i32 32767, i32 32768
%ptr.slide = getelementptr i8, ptr %obj, i32 %offset
%objsize_max = call i32 @llvm.objectsize.i32.p0(ptr %ptr.slide, i1 false, i1 true, i1 false)
%objsize_min = call i32 @llvm.objectsize.i32.p0(ptr %ptr.slide, i1 true, i1 true, i1 false)
%res = select i1 %c1, i32 %objsize_max, i32 %objsize_min
ret i32 %res
}

; FIXME: Is 3 really correct for %objsize_min here?
define i32 @possible_out_of_bounds_gep_i8_neg(i1 %c0, i1 %c1) {
; CHECK-LABEL: define i32 @possible_out_of_bounds_gep_i8_neg(
; CHECK-SAME: i1 [[C0:%.*]], i1 [[C1:%.*]]) {
; CHECK-NEXT: [[ENTRY:.*:]]
; CHECK-NEXT: [[RES:%.*]] = select i1 [[C1]], i32 -1, i32 3
; CHECK-NEXT: ret i32 [[RES]]
;
entry:
%obj = alloca [5 x i8]
%offset = select i1 %c0, i8 2, i8 -10
%ptr.slide = getelementptr i8, ptr %obj, i8 %offset
%objsize_max = call i32 @llvm.objectsize.i32.p0(ptr %ptr.slide, i1 false, i1 true, i1 false)
%objsize_min = call i32 @llvm.objectsize.i32.p0(ptr %ptr.slide, i1 true, i1 true, i1 false)
%res = select i1 %c1, i32 %objsize_max, i32 %objsize_min
ret i32 %res
}

; FIXME: Is 3 really correct for %objsize_min here?
define i32 @possible_out_of_bounds_gep_i16_neg(i1 %c0, i1 %c1) {
; CHECK-LABEL: define i32 @possible_out_of_bounds_gep_i16_neg(
; CHECK-SAME: i1 [[C0:%.*]], i1 [[C1:%.*]]) {
; CHECK-NEXT: [[ENTRY:.*:]]
; CHECK-NEXT: [[RES:%.*]] = select i1 [[C1]], i32 -1, i32 3
; CHECK-NEXT: ret i32 [[RES]]
;
entry:
%obj = alloca [5 x i8]
%offset = select i1 %c0, i16 2, i16 -10
%ptr.slide = getelementptr i8, ptr %obj, i16 %offset
%objsize_max = call i32 @llvm.objectsize.i32.p0(ptr %ptr.slide, i1 false, i1 true, i1 false)
%objsize_min = call i32 @llvm.objectsize.i32.p0(ptr %ptr.slide, i1 true, i1 true, i1 false)
%res = select i1 %c1, i32 %objsize_max, i32 %objsize_min
ret i32 %res
}
57 changes: 53 additions & 4 deletions llvm/test/Transforms/LowerConstantIntrinsics/builtin-object-size-phi.ll
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Original file line number Diff line number Diff line change
Expand Up @@ -200,8 +200,12 @@ if.end:
ret i64 %size
}

define i64 @pick_negative_offset_different_width(i32 %n) {
; CHECK-LABEL: @pick_negative_offset_different_width(
; FIXME: The result here looks weird. Either we reference into buffer0 with an
; oob offset. Or we reference buffer1 (8 bytes) with a 4 byte
; offset. The result 5 is wrong in both cases. Probably better to
; return -1 here since we do not know if we have an oob pointer.
define i64 @pick_negative_offset_different_width_index_maybe_too_small(i32 %n, i1 %c) {
; CHECK-LABEL: @pick_negative_offset_different_width_index_maybe_too_small(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[BUFFER0:%.*]] = alloca i8, i64 4, align 1
; CHECK-NEXT: [[BUFFER1:%.*]] = alloca i8, i64 8, align 1
Expand All @@ -216,7 +220,8 @@ define i64 @pick_negative_offset_different_width(i32 %n) {
; CHECK: if.end:
; CHECK-NEXT: [[P:%.*]] = phi ptr [ [[OFFSETED0]], [[IF_ELSE]] ], [ [[OFFSETED1]], [[IF_END]] ]
; CHECK-NEXT: [[POFFSETED:%.*]] = getelementptr i8, ptr [[P]], i64 -2
; CHECK-NEXT: ret i64 5
; CHECK-NEXT: [[SIZE:%.*]] = select i1 [[C:%.*]], i64 5, i64 0
; CHECK-NEXT: ret i64 [[SIZE]]
;
entry:
%buffer0 = alloca i8, i64 4
Expand All @@ -235,7 +240,51 @@ if.else:
if.end:
%p = phi ptr [ %offseted0, %if.then ], [ %offseted1, %if.else ]
%poffseted = getelementptr i8, ptr %p, i64 -2
%size = call i64 @llvm.objectsize.i64.p0(ptr %poffseted, i1 false, i1 false, i1 false)
%sizemax = call i64 @llvm.objectsize.i64.p0(ptr %poffseted, i1 false, i1 false, i1 false)
%sizemin = call i64 @llvm.objectsize.i64.p0(ptr %poffseted, i1 true, i1 false, i1 false)
%size = select i1 %c, i64 %sizemax, i64 %sizemin
ret i64 %size
}

define i64 @pick_negative_offset_different_width_index_maybe_too_large(i32 %n, i1 %c) {
; CHECK-LABEL: @pick_negative_offset_different_width_index_maybe_too_large(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[BUFFER0:%.*]] = alloca i8, i64 4, align 1
; CHECK-NEXT: [[BUFFER1:%.*]] = alloca i8, i64 8, align 1
; CHECK-NEXT: [[COND:%.*]] = icmp eq i32 [[N:%.*]], 0
; CHECK-NEXT: br i1 [[COND]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
; CHECK: if.then:
; CHECK-NEXT: [[OFFSETED0:%.*]] = getelementptr i8, ptr [[BUFFER0]], i64 1
; CHECK-NEXT: br label [[IF_END:%.*]]
; CHECK: if.else:
; CHECK-NEXT: [[OFFSETED1:%.*]] = getelementptr i8, ptr [[BUFFER1]], i64 6
; CHECK-NEXT: br label [[IF_END]]
; CHECK: if.end:
; CHECK-NEXT: [[P:%.*]] = phi ptr [ [[OFFSETED0]], [[IF_THEN]] ], [ [[OFFSETED1]], [[IF_ELSE]] ]
; CHECK-NEXT: [[POFFSETED:%.*]] = getelementptr i8, ptr [[P]], i64 2
; CHECK-NEXT: [[SIZE:%.*]] = select i1 [[C:%.*]], i64 1, i64 0
; CHECK-NEXT: ret i64 [[SIZE]]
;
entry:
%buffer0 = alloca i8, i64 4
%buffer1 = alloca i8, i64 8
%cond = icmp eq i32 %n, 0
br i1 %cond, label %if.then, label %if.else

if.then:
%offseted0 = getelementptr i8, ptr %buffer0, i64 1
br label %if.end

if.else:
%offseted1 = getelementptr i8, ptr %buffer1, i64 6
br label %if.end

if.end:
%p = phi ptr [ %offseted0, %if.then ], [ %offseted1, %if.else ]
%poffseted = getelementptr i8, ptr %p, i64 2
%sizemax = call i64 @llvm.objectsize.i64.p0(ptr %poffseted, i1 false, i1 false, i1 false)
%sizemin = call i64 @llvm.objectsize.i64.p0(ptr %poffseted, i1 true, i1 false, i1 false)
%size = select i1 %c, i64 %sizemax, i64 %sizemin
ret i64 %size
}

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