# Prevent the machine scheduler from moving instructions past FAKE_USE.
# RUN: llc -run-pass machine-scheduler -mtriple=x86_64-unknown-linux -debug-only=machine-scheduler 2>&1 -o - %s | FileCheck %s
# REQUIRES: asserts
#
# We make sure that, beginning with the first FAKE_USE instruction,
# no changes to the sequence of instructions are undertaken by the
# scheduler. We don't bother to check that the order of the FAKE_USEs
# remains the same. They should, but it is irrelevant.
#
# CHECK: ********** MI Scheduling **********
# CHECK-NEXT: foo:%bb.0 entry
# CHECK-NEXT: From: %0:gr64 = COPY $rdi
# CHECK-NEXT: To: FAKE_USE %5:gr64
# CHECK-NEXT: RegionInstrs: 7
#
# CHECK: ********** MI Scheduling **********
# CHECK-NEXT: bar:%bb.0 entry
# CHECK-NEXT: From: %0:gr64 = COPY $rdi
# CHECK-NEXT: To: RET 0, killed $rax
# CHECK-NEXT: RegionInstrs: 7
#
--- |
; ModuleID = 'test.ll'
source_filename = "test.ll"
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
@glb = common dso_local local_unnamed_addr global [100 x i32] zeroinitializer, align 16
define dso_local i64 @foo(ptr %p) local_unnamed_addr optdebug {
entry:
%0 = load i32, ptr @glb, align 16
store i32 %0, ptr %p, align 4
%conv = sext i32 %0 to i64
%1 = load i32, ptr getelementptr inbounds ([100 x i32], ptr @glb, i64 0, i64 1), align 4
%arrayidx1 = getelementptr inbounds i32, ptr %p, i64 1
store i32 %1, ptr %arrayidx1, align 4
%conv2 = sext i32 %1 to i64
%add3 = add nsw i64 %conv2, %conv
notail call void (...) @llvm.fake.use(i64 %add3)
notail call void (...) @llvm.fake.use(i32 %1)
notail call void (...) @llvm.fake.use(i32 %0)
notail call void (...) @llvm.fake.use(ptr %p)
ret i64 %add3
}
define dso_local i64 @bar(ptr %p) local_unnamed_addr optdebug {
entry:
%0 = load i32, ptr @glb, align 16
store i32 %0, ptr %p, align 4
%conv = sext i32 %0 to i64
%1 = load i32, ptr getelementptr inbounds ([100 x i32], ptr @glb, i64 0, i64 1), align 4
%arrayidx1 = getelementptr inbounds i32, ptr %p, i64 1
store i32 %1, ptr %arrayidx1, align 4
%conv2 = sext i32 %1 to i64
%add3 = add nsw i64 %conv2, %conv
ret i64 %add3
}
; Function Attrs: nocallback nofree nosync nounwind willreturn
declare void @llvm.stackprotector(ptr, ptr)
...
---
name: foo
alignment: 16
tracksRegLiveness: true
debugInstrRef: true
registers:
- { id: 0, class: gr64, preferred-register: '' }
- { id: 1, class: gr64_with_sub_8bit, preferred-register: '' }
- { id: 2, class: gr32, preferred-register: '' }
- { id: 3, class: gr64_with_sub_8bit, preferred-register: '' }
- { id: 4, class: gr32, preferred-register: '' }
- { id: 5, class: gr64, preferred-register: '' }
liveins:
- { reg: '$rdi', virtual-reg: '%0' }
body: |
bb.0.entry:
liveins: $rdi
%0:gr64 = COPY $rdi
%1:gr64_with_sub_8bit = MOVSX64rm32 $rip, 1, $noreg, @glb, $noreg
MOV32mr %0, 1, $noreg, 0, $noreg, %1.sub_32bit
%3:gr64_with_sub_8bit = MOVSX64rm32 $rip, 1, $noreg, @glb + 4, $noreg
MOV32mr %0, 1, $noreg, 4, $noreg, %3.sub_32bit
%5:gr64 = COPY %3
%5:gr64 = nsw ADD64rr %5, %1, implicit-def dead $eflags
FAKE_USE %5
FAKE_USE %3.sub_32bit
FAKE_USE %1.sub_32bit
FAKE_USE %0
$rax = COPY %5
RET 0, killed $rax
...
---
name: bar
alignment: 16
tracksRegLiveness: true
debugInstrRef: true
registers:
- { id: 0, class: gr64, preferred-register: '' }
- { id: 1, class: gr64_with_sub_8bit, preferred-register: '' }
- { id: 2, class: gr32, preferred-register: '' }
- { id: 3, class: gr64_with_sub_8bit, preferred-register: '' }
- { id: 4, class: gr32, preferred-register: '' }
- { id: 5, class: gr64_with_sub_8bit, preferred-register: '' }
liveins:
- { reg: '$rdi', virtual-reg: '%0' }
body: |
bb.0.entry:
liveins: $rdi
%0:gr64 = COPY $rdi
%1:gr64_with_sub_8bit = MOVSX64rm32 $rip, 1, $noreg, @glb, $noreg
MOV32mr %0, 1, $noreg, 0, $noreg, %1.sub_32bit
%5:gr64_with_sub_8bit = MOVSX64rm32 $rip, 1, $noreg, @glb + 4, $noreg
MOV32mr %0, 1, $noreg, 4, $noreg, %5.sub_32bit
%5:gr64_with_sub_8bit = nsw ADD64rr %5, %1, implicit-def dead $eflags
$rax = COPY %5
RET 0, killed $rax
...
Codebase Browser
llvm