mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2025-02-01 05:01:59 +01:00
f73282e3d5
If a call argument has the "returned" attribute, we can simplify the call to the value of that argument. This was already partially handled by InstSimplify/InstCombine for the case where the argument is an integer constant, and the result is thus known via known bits. The non-constant (or non-int) argument cases weren't handled though. This previously landed as an InstSimplify transform, but was reverted due to assertion failures when compiling the Linux kernel. The reason is that simplifying a call to another call breaks assumptions in call graph updating during inlining. As the code is not easy to fix, and there is no particularly strong motivation for having this in InstSimplify, the transform is only performed in InstCombine instead. Differential Revision: https://reviews.llvm.org/D75815
50 lines
1.5 KiB
LLVM
50 lines
1.5 KiB
LLVM
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --function-signature
|
|
; RUN: opt -S -O3 -o - %s | FileCheck %s
|
|
|
|
; PR44154: LLVM c3b06d0c393e caused the body of @main to be replaced with
|
|
; unreachable. Check that we perform the expected calls and optimizations.
|
|
|
|
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
|
|
target triple = "x86_64-unknown-linux-gnu"
|
|
|
|
define i32 @main(i32 %argc, i8** %argv) #0 {
|
|
; CHECK-LABEL: define {{[^@]+}}@main
|
|
; CHECK-SAME: (i32 [[ARGC:%.*]], i8** nocapture readnone [[ARGV:%.*]]) local_unnamed_addr #0
|
|
; CHECK-NEXT: entry:
|
|
; CHECK-NEXT: [[TMP0:%.*]] = icmp slt i32 [[ARGC]], 2
|
|
; CHECK-NEXT: [[SPEC_SELECT:%.*]] = select i1 [[TMP0]], i32 0, i32 [[ARGC]]
|
|
; CHECK-NEXT: ret i32 [[SPEC_SELECT]]
|
|
;
|
|
entry:
|
|
%0 = getelementptr inbounds i8*, i8** %argv, i32 0
|
|
%ptr = load i8*, i8** %0
|
|
%1 = call i32 @compute(i8* %ptr, i32 %argc)
|
|
%2 = icmp slt i32 %argc, 2
|
|
br i1 %2, label %done, label %do_work
|
|
|
|
do_work:
|
|
%3 = icmp eq i8* %ptr, null
|
|
br i1 %3, label %null, label %done
|
|
|
|
null:
|
|
call void @call_if_null(i8* %ptr)
|
|
br label %done
|
|
|
|
done:
|
|
%retval = phi i32 [0, %entry], [%1, %do_work], [%1, %null]
|
|
ret i32 %retval
|
|
}
|
|
|
|
define i32 @compute(i8* nonnull %ptr, i32 %x) #1 {
|
|
; CHECK-LABEL: define {{[^@]+}}@compute
|
|
; CHECK-SAME: (i8* nocapture nonnull readnone [[PTR:%.*]], i32 returned [[X:%.*]]) local_unnamed_addr #1
|
|
; CHECK-NEXT: ret i32 [[X]]
|
|
;
|
|
ret i32 %x
|
|
}
|
|
|
|
declare void @call_if_null(i8* %ptr) #0
|
|
|
|
attributes #0 = { nounwind }
|
|
attributes #1 = { noinline nounwind readonly }
|