dbeaf6baa2
When calculating the specialization bonus for a given function argument, we recursively traverse the chain of (certain) users, accumulating the instruction costs. Then we exponentially increase the bonus to account for loop nests. This is problematic for two reasons: (a) the users might not themselves be inside the loop nest, (b) if they are we are accounting for it multiple times. Instead we should be adjusting the bonus before traversing the user chain. This reduces the instruction count for CTMark (newPM-O3) when Function Specialization is enabled without actually reducing the amount of specializations performed (geomean: -0.001% non-LTO, -0.406% LTO). Differential Revision: https://reviews.llvm.org/D136692
64 lines
1.5 KiB
LLVM
64 lines
1.5 KiB
LLVM
; RUN: opt -function-specialization -func-specialization-avg-iters-cost=5 -func-specialization-size-threshold=10 -S < %s | FileCheck %s
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; Check that the loop depth results in a larger specialization bonus.
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; CHECK: @foo.1(
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; CHECK: @foo.2(
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target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"
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@A = external dso_local constant i32, align 4
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@B = external dso_local constant i32, align 4
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@C = external dso_local constant i32, align 4
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@D = external dso_local constant i32, align 4
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declare i1 @cond_begin()
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declare i1 @cond_end()
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declare i1 @getCond()
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define internal i32 @foo(i32 %x, i32* %b, i32* %c) {
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entry:
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br label %loop.entry
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loop.entry:
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br label %loop2.entry
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loop2.entry:
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br label %loop2.body
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loop2.body:
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%0 = load i32, i32* %b, align 4
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%1 = load i32, i32* %c, align 4
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%add.0 = add nsw i32 %0, %1
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%add = add nsw i32 %add.0, %x
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br label %loop2.end
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loop2.end:
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%cond.end = call i1 @cond_end()
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br i1 %cond.end, label %loop2.entry, label %loop.end
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loop.end:
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%cond2.end = call i1 @getCond()
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br i1 %cond2.end, label %loop.entry, label %return
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return:
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ret i32 %add
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}
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define dso_local i32 @bar(i32 %x, i32 %y) {
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entry:
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%tobool = icmp ne i32 %x, 0
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br i1 %tobool, label %if.then, label %if.else
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if.then:
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%call = call i32 @foo(i32 %x, i32* @A, i32* @C)
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br label %return
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if.else:
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%call1 = call i32 @foo(i32 %y, i32* @B, i32* @D)
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br label %return
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return:
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%retval.0 = phi i32 [ %call, %if.then ], [ %call1, %if.else ]
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ret i32 %retval.0
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}
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