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

[Björn Pettersson via llvm-commits]

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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
+; 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) {
----------------
bjope wrote:

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.)

https://github.com/llvm/llvm-project/pull/132364