Nikita Popov 29441e4f5f
[IR] Convert from nocapture to captures(none) (#123181)
This PR removes the old `nocapture` attribute, replacing it with the new
`captures` attribute introduced in #116990. This change is
intended to be essentially NFC, replacing existing uses of `nocapture`
with `captures(none)` without adding any new analysis capabilities.
Making use of non-`none` values is left for a followup.

Some notes:
* `nocapture` will be upgraded to `captures(none)` by the bitcode
   reader.
* `nocapture` will also be upgraded by the textual IR reader. This is to
   make it easier to use old IR files and somewhat reduce the test churn in
   this PR.
* Helper APIs like `doesNotCapture()` will check for `captures(none)`.
* MLIR import will convert `captures(none)` into an `llvm.nocapture`
   attribute. The representation in the LLVM IR dialect should be updated
   separately.
2025-01-29 16:56:47 +01:00

29 lines
1.3 KiB
LLVM

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4
; RUN: opt < %s -passes=memcpyopt,instcombine -S -verify-memoryssa | FileCheck --check-prefix=CUSTOM %s
; RUN: opt < %s -O2 -S | FileCheck --check-prefix=O2 %s
; Check that we eliminate all `memcpy` calls in this function.
define void @memcpy_forward_back_with_offset(ptr %arg) {
; CUSTOM-LABEL: define void @memcpy_forward_back_with_offset(
; CUSTOM-SAME: ptr [[ARG:%.*]]) {
; CUSTOM-NEXT: store i8 1, ptr [[ARG]], align 1
; CUSTOM-NEXT: ret void
;
; O2-LABEL: define void @memcpy_forward_back_with_offset(
; O2-SAME: ptr writeonly captures(none) initializes((0, 1)) [[ARG:%.*]]) local_unnamed_addr #[[ATTR0:[0-9]+]] {
; O2-NEXT: store i8 1, ptr [[ARG]], align 1
; O2-NEXT: ret void
;
%i = alloca [753 x i8], align 1
%i1 = alloca [754 x i8], align 1
call void @llvm.memcpy.p0.p0.i64(ptr %i1, ptr %arg, i64 754, i1 false)
%i2 = getelementptr inbounds i8, ptr %i1, i64 1
call void @llvm.memcpy.p0.p0.i64(ptr %i, ptr %i2, i64 753, i1 false)
store i8 1, ptr %arg, align 1
%i3 = getelementptr inbounds i8, ptr %arg, i64 1
call void @llvm.memcpy.p0.p0.i64(ptr %i3, ptr %i, i64 753, i1 false)
ret void
}
declare void @llvm.memcpy.p0.p0.i64(ptr, ptr, i64, i1)