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llvm-project/llvm/test/Transforms/CountingFunctionInserter/mcount.ll

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Add a counter-function insertion pass As discussed in https://reviews.llvm.org/D22666, our current mechanism to support -pg profiling, where we insert calls to mcount(), or some similar function, is fundamentally broken. We insert these calls in the frontend, which means they get duplicated when inlining, and so the accumulated execution counts for the inlined-into functions are wrong. Because we don't want the presence of these functions to affect optimizaton, they should be inserted in the backend. Here's a pass which would do just that. The knowledge of the name of the counting function lives in the frontend, so we're passing it here as a function attribute. Clang will be updated to use this mechanism. Differential Revision: https://reviews.llvm.org/D22825 llvm-svn: 280347
2016-09-01 17:42:39 +08:00
; RUN: opt -S -cfinserter < %s | FileCheck %s
target datalayout = "E-m:e-i64:64-n32:64"
target triple = "powerpc64-bgq-linux"
define void @test1() #0 {
entry:
ret void
; CHECK-LABEL: define void @test1()
; CHECK: entry:
; CHECK-NEXT: call void @mcount()
; CHECK: ret void
}
define void @test2() #1 {
entry:
ret void
; CHECK-LABEL: define void @test2()
; CHECK: entry:
; CHECK-NEXT: call void @.mcount()
; CHECK: ret void
}
attributes #0 = { "counting-function"="mcount" }
attributes #1 = { "counting-function"=".mcount" }