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[NewPM][Inliner] Make inlined calls to functions in same SCC as calle…
…e exponentially expensive Introduce a new attribute "function-inline-cost-multiplier" which multiplies the inline cost of a call site (or all calls to a callee) by the multiplier. When processing the list of calls created by inlining, check each call to see if the new call's callee is in the same SCC as the original callee. If so, set the "function-inline-cost-multiplier" attribute of the new call site to double the original call site's attribute value. This does not happen when the original call site is intra-SCC. This is an alternative to D120584, which marks the call sites as noinline. Hopefully fixes PR45253. Reviewed By: davidxl Differential Revision: https://reviews.llvm.org/D121084
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Original file line number | Diff line number | Diff line change |
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; RUN: opt -S -passes='inline' < %s | FileCheck %s | ||
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; Make sure we don't mark calls within the same SCC as original function with noinline. | ||
; CHECK-NOT: function-inline-cost-multiplier | ||
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define void @samescc1() { | ||
call void @samescc2() | ||
ret void | ||
} | ||
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define void @samescc2() { | ||
call void @samescc3() | ||
ret void | ||
} | ||
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define void @samescc3() { | ||
call void @samescc1() | ||
ret void | ||
} |
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Original file line number | Diff line number | Diff line change |
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; RUN: opt -S -passes='cgscc(inline,instcombine)' < %s | FileCheck %s | ||
; RUN: opt -S -intra-scc-cost-multiplier=3 -passes='cgscc(inline,instcombine)' < %s | FileCheck %s --check-prefix=THREE | ||
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; We use call to a dummy function to avoid inlining test1 into test2 or vice | ||
; versa, such that we aren't left with a trivial cycle, as trivial cycles are | ||
; special-cased to never be inlined. | ||
; However, InstCombine will eliminate these calls after inlining, and thus | ||
; make the functions eligible for inlining in their callers. | ||
declare void @dummy() readnone nounwind willreturn | ||
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define void @test1() { | ||
; CHECK-LABEL: define void @test1( | ||
; CHECK-NEXT: call void @test2() | ||
; CHECK-NEXT: call void @test2() | ||
; CHECK-NEXT: ret void | ||
; | ||
call void @test2() | ||
call void @test2() | ||
call void @dummy() | ||
call void @dummy() | ||
call void @dummy() | ||
call void @dummy() | ||
call void @dummy() | ||
call void @dummy() | ||
call void @dummy() | ||
call void @dummy() | ||
call void @dummy() | ||
call void @dummy() | ||
call void @dummy() | ||
ret void | ||
} | ||
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define void @test2() { | ||
; CHECK-LABEL: define void @test2( | ||
; CHECK-NEXT: call void @test1() | ||
; CHECK-NEXT: call void @test1() | ||
; CHECK-NEXT: ret void | ||
; | ||
call void @test1() | ||
call void @test1() | ||
call void @dummy() | ||
call void @dummy() | ||
call void @dummy() | ||
call void @dummy() | ||
call void @dummy() | ||
call void @dummy() | ||
call void @dummy() | ||
call void @dummy() | ||
call void @dummy() | ||
call void @dummy() | ||
call void @dummy() | ||
ret void | ||
} | ||
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; The inlined call sites should have the "function-inline-cost-multiplier" call site attribute. | ||
; This test is a bit fragile in the exact number of inlining that happens based on thresholds. | ||
define void @test3() { | ||
; CHECK-LABEL: define void @test3( | ||
; CHECK-NEXT: call void @test2() #[[COSTMULT:[0-9]+]] | ||
; CHECK-NEXT: call void @test2() #[[COSTMULT]] | ||
; CHECK-NEXT: call void @test2() #[[COSTMULT]] | ||
; CHECK-NEXT: call void @test2() #[[COSTMULT]] | ||
; CHECK-NEXT: call void @test2() #[[COSTMULT]] | ||
; CHECK-NEXT: call void @test2() #[[COSTMULT]] | ||
; CHECK-NEXT: call void @test2() #[[COSTMULT]] | ||
; CHECK-NEXT: call void @test2() #[[COSTMULT]] | ||
; CHECK-NEXT: ret void | ||
; | ||
call void @test2() | ||
call void @test2() | ||
ret void | ||
} | ||
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; CHECK: [[COSTMULT]] = { "function-inline-cost-multiplier"="4" } | ||
; THREE: "function-inline-cost-multiplier"="9" |