273c299d5d
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
38 lines
988 B
LLVM
38 lines
988 B
LLVM
; RUN: opt -hotcoldsplit -hotcoldsplit-threshold=-1 -pass-remarks=hotcoldsplit -S < %s 2>&1 | FileCheck %s
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; RUN: opt -passes=hotcoldsplit -hotcoldsplit-threshold=-1 -pass-remarks=hotcoldsplit -S < %s 2>&1 | FileCheck %s
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; Make sure this compiles. This test used to fail with an invalid phi node: the
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; two predecessors were outlined and the SSA representation was invalid.
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; CHECK: remark: <unknown>:0:0: fun split cold code into fun.cold.1
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; CHECK-LABEL: @fun
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; CHECK: codeRepl:
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; CHECK-NEXT: call void @fun.cold.1
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; CHECK: define {{.*}}@fun.cold.1{{.*}} [[cold_attr:#[0-9]+]]
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; CHECK: attributes [[cold_attr]] = { {{.*}}noreturn
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define void @fun() "hot-cold-split" {
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entry:
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br i1 undef, label %if.then, label %if.else
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if.then:
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ret void
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if.else:
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br label %if.then4
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if.then4:
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br i1 undef, label %if.then5, label %if.end
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if.then5:
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br label %cleanup
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if.end:
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br label %cleanup
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cleanup:
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%cleanup.dest.slot.0 = phi i32 [ 1, %if.then5 ], [ 0, %if.end ]
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unreachable
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}
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