| ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py |
| ; RUN: opt < %s -instcombine -S | FileCheck %s |
| |
| ; See https://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20210412/904154.html |
| ; When replacing an allocation that is only modified by a memcpy/memmove from |
| ; a constant whose alignment is equal to or exceeds that of the allocation, |
| ; we also need to ensure that we actually can replace all uses of an alloca |
| ; with said constant. This matters because it could be e.g. a select between |
| ; two constants, that happens after the first use of an alloca. |
| |
| %t0 = type { i8*, i64 } |
| |
| @g0 = external constant %t0 |
| @g1 = external constant %t0 |
| define void @test(i8*%out) { |
| ; CHECK-LABEL: @test( |
| ; CHECK-NEXT: [[I0:%.*]] = alloca [[T0:%.*]], align 8 |
| ; CHECK-NEXT: [[I1:%.*]] = bitcast %t0* [[I0]] to i8* |
| ; CHECK-NEXT: [[I2:%.*]] = call i1 @get_cond() |
| ; CHECK-NEXT: [[I3:%.*]] = select i1 [[I2]], i8* bitcast (%t0* @g0 to i8*), i8* bitcast (%t0* @g1 to i8*) |
| ; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i64(i8* noundef nonnull align 8 dereferenceable(16) [[I1]], i8* noundef nonnull align 8 dereferenceable(16) [[I3]], i64 16, i1 false) |
| ; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i64(i8* noundef nonnull align 1 dereferenceable(16) [[OUT:%.*]], i8* noundef nonnull align 8 dereferenceable(16) [[I1]], i64 16, i1 false) |
| ; CHECK-NEXT: ret void |
| ; |
| %i0 = alloca %t0 |
| %i1 = bitcast %t0* %i0 to i8* |
| %i2 = call i1 @get_cond() |
| %i3 = select i1 %i2, i8* bitcast (%t0* @g0 to i8*), i8* bitcast (%t0* @g1 to i8*) |
| call void @llvm.memcpy.p0i8.p0i8.i64(i8* %i1, i8* %i3, i64 16, i1 false) |
| call void @llvm.memcpy.p0i8.p0i8.i64(i8* %out, i8* %i1, i64 16, i1 false) |
| ret void |
| } |
| |
| declare i1 @get_cond() |
| declare void @llvm.memcpy.p0i8.p0i8.i64(i8*, i8*, i64, i1) |
