0628bea513
This broke Chromium's PGO build, it seems because hot-cold-splitting got turned
on unintentionally. See comment on the code review for repro etc.
> This patch adds -f[no-]split-cold-code CC1 options to clang. This allows
> the splitting pass to be toggled on/off. The current method of passing
> `-mllvm -hot-cold-split=true` to clang isn't ideal as it may not compose
> correctly (say, with `-O0` or `-Oz`).
>
> To implement the -fsplit-cold-code option, an attribute is applied to
> functions to indicate that they may be considered for splitting. This
> removes some complexity from the old/new PM pipeline builders, and
> behaves as expected when LTO is enabled.
>
> Co-authored by: Saleem Abdulrasool <compnerd@compnerd.org>
> Differential Revision: https://reviews.llvm.org/D57265
> Reviewed By: Aditya Kumar, Vedant Kumar
> Reviewers: Teresa Johnson, Aditya Kumar, Fedor Sergeev, Philip Pfaffe, Vedant Kumar
This reverts commit 273c299d5d.
65 lines
1.7 KiB
LLVM
65 lines
1.7 KiB
LLVM
; RUN: opt -S -hotcoldsplit -hotcoldsplit-threshold=0 < %s | FileCheck %s
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; Source:
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;
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; extern void sideeffect(int);
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; extern void __attribute__((cold)) sink();
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; void foo(int cond) {
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; if (cond) { //< Start outlining here.
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; if (cond > 10)
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; sideeffect(0);
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; else
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; sideeffect(1);
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; sink();
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; }
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; sideeffect(2);
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; }
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target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
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target triple = "x86_64-apple-macosx10.14.0"
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; CHECK-LABEL: define {{.*}}@foo(
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; CHECK: br i1 {{.*}}, label %codeRepl, label %if.end2
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; CHECK-LABEL: codeRepl:
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; CHECK-NEXT: call void @foo.cold.1
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; CHECK-LABEL: if.end2:
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; CHECK: call void @sideeffect(i32 2)
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define void @foo(i32 %cond) {
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entry:
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%cond.addr = alloca i32
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store i32 %cond, i32* %cond.addr
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%0 = load i32, i32* %cond.addr
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%tobool = icmp ne i32 %0, 0
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br i1 %tobool, label %if.then, label %if.end2
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if.then: ; preds = %entry
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%1 = load i32, i32* %cond.addr
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%cmp = icmp sgt i32 %1, 10
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br i1 %cmp, label %if.then1, label %if.else
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if.then1: ; preds = %if.then
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call void @sideeffect(i32 0)
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br label %if.end
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if.else: ; preds = %if.then
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call void @sideeffect(i32 1)
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br label %if.end
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if.end: ; preds = %if.else, %if.then1
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call void (...) @sink()
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ret void
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if.end2: ; preds = %entry
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call void @sideeffect(i32 2)
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ret void
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}
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; CHECK-LABEL: define {{.*}}@foo.cold.1
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; CHECK: call {{.*}}@sideeffect
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; CHECK: call {{.*}}@sideeffect
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; CHECK: call {{.*}}@sink
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declare void @sideeffect(i32)
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declare void @sink(...) cold
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