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Place the "cold" code piece into the same section as the original function 

Summary:
This cropped up in the Linux kernel where cold code was placed in an
incompatible section.

Reviewers: compnerd, vsk, tejohnson

Reviewed By: vsk

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70925
This commit is contained in:
Bill Wendling 2019-12-01 23:22:50 -08:00
parent 536cedaecb
commit 87f146767e
2 changed files with 36 additions and 0 deletions
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3
llvm/lib/Transforms/IPO/HotColdSplitting.cpp
View File

@ -328,6 +328,9 @@ Function *HotColdSplitting::extractColdRegion(
}
CI->setIsNoInline();
if (OrigF->hasSection())
OutF->setSection(OrigF->getSection());
markFunctionCold(*OutF, BFI != nullptr);
LLVM_DEBUG(llvm::dbgs() << "Outlined Region: " << *OutF);

33
llvm/test/Transforms/HotColdSplit/retain-section.ll Normal file
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@ -0,0 +1,33 @@
; RUN: opt -hotcoldsplit -hotcoldsplit-threshold=0 -S < %s | FileCheck %s
target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-apple-macosx10.14.0"
; Retain section after cold code is split off.
; CHECK-LABEL: @fun
; CHECK: call void @fun.cold.1{{.*}} section ".text.cold"
define void @fun() section ".text.cold" {
entry:
br i1 undef, label %if.then, label %if.else
if.then:
ret void
if.else:
call void @sink()
ret void
}
; CHECK: define {{.*}} @foo{{.*}}#[[outlined_func_attr:[0-9]+]]
define void @foo() cold {
ret void
}
declare void @sink() cold
; CHECK: define {{.*}} @fun.cold.1{{.*}}#[[outlined_func_attr]]
; CHECK: attributes #[[outlined_func_attr]] = {
; CHECK-SAME: cold
; CHECK-SAME: minsize