llvm/test/Transforms/LoopDistribute/metadata.ll
Adam Nemet 8d171c8f85 [LoopDist] Add llvm.loop.distribute.enable loop metadata
Summary:
D19403 adds a new pragma for loop distribution.  This change adds
support for the corresponding metadata that the pragma is translated to
by the FE.

As part of this I had to rethink the flag -enable-loop-distribute.  My
goal was to be backward compatible with the existing behavior:

  A1. pass is off by default from the optimization pipeline
  unless -enable-loop-distribute is specified

  A2. pass is on when invoked directly from opt (e.g. for unit-testing)

The new pragma/metadata overrides these defaults so the new behavior is:

  B1. A1 + enable distribution for individual loop with the pragma/metadata

  B2. A2 + disable distribution for individual loop with the pragma/metadata

The default value whether the pass is on or off comes from the initiator
of the pass.  From the PassManagerBuilder the default is off, from opt
it's on.

I moved -enable-loop-distribute under the pass.  If the flag is
specified it overrides the default from above.

Then the pragma/metadata can further modifies this per loop.

As a side-effect, we can now also use -enable-loop-distribute=0 from opt
to emulate the default from the optimization pipeline.  So to be precise
this is the new behavior:

  C1. pass is off by default from the optimization pipeline
  unless -enable-loop-distribute or the pragma/metadata enables it

  C2. pass is on when invoked directly from opt
  unless -enable-loop-distribute=0 or the pragma/metadata disables it

Reviewers: hfinkel

Subscribers: joker.eph, mzolotukhin, llvm-commits

Differential Revision: http://reviews.llvm.org/D19431

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267672 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-27 05:28:18 +00:00

150 lines
4.8 KiB
LLVM

; RUN: opt -basicaa -loop-distribute -enable-loop-distribute=0 -S < %s | FileCheck %s --check-prefix=CHECK --check-prefix=EXPLICIT --check-prefix=DEFAULT_OFF
; RUN: opt -basicaa -loop-distribute -enable-loop-distribute=1 -S < %s | FileCheck %s --check-prefix=CHECK --check-prefix=EXPLICIT --check-prefix=DEFAULT_ON
; Same loop as in basic.ll. Check that distribution is enabled/disabled
; properly according to -enable-loop-distribute=0/1 and the
; llvm.loop.distribute.enable metadata.
target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-apple-macosx10.10.0"
; CHECK-LABEL: @explicit_on(
define void @explicit_on(i32* noalias %a,
i32* noalias %b,
i32* noalias %c,
i32* noalias %d,
i32* noalias %e) {
entry:
br label %for.body
; EXPLICIT: for.body.ldist1:
for.body: ; preds = %for.body, %entry
%ind = phi i64 [ 0, %entry ], [ %add, %for.body ]
%arrayidxA = getelementptr inbounds i32, i32* %a, i64 %ind
%loadA = load i32, i32* %arrayidxA, align 4
%arrayidxB = getelementptr inbounds i32, i32* %b, i64 %ind
%loadB = load i32, i32* %arrayidxB, align 4
%mulA = mul i32 %loadB, %loadA
%add = add nuw nsw i64 %ind, 1
%arrayidxA_plus_4 = getelementptr inbounds i32, i32* %a, i64 %add
store i32 %mulA, i32* %arrayidxA_plus_4, align 4
%arrayidxD = getelementptr inbounds i32, i32* %d, i64 %ind
%loadD = load i32, i32* %arrayidxD, align 4
%arrayidxE = getelementptr inbounds i32, i32* %e, i64 %ind
%loadE = load i32, i32* %arrayidxE, align 4
%mulC = mul i32 %loadD, %loadE
%arrayidxC = getelementptr inbounds i32, i32* %c, i64 %ind
store i32 %mulC, i32* %arrayidxC, align 4
%exitcond = icmp eq i64 %add, 20
br i1 %exitcond, label %for.end, label %for.body, !llvm.loop !0
for.end: ; preds = %for.body
ret void
}
; CHECK-LABEL: @explicit_off(
define void @explicit_off(i32* noalias %a,
i32* noalias %b,
i32* noalias %c,
i32* noalias %d,
i32* noalias %e) {
entry:
br label %for.body
; EXPLICIT-NOT: for.body.ldist1:
for.body: ; preds = %for.body, %entry
%ind = phi i64 [ 0, %entry ], [ %add, %for.body ]
%arrayidxA = getelementptr inbounds i32, i32* %a, i64 %ind
%loadA = load i32, i32* %arrayidxA, align 4
%arrayidxB = getelementptr inbounds i32, i32* %b, i64 %ind
%loadB = load i32, i32* %arrayidxB, align 4
%mulA = mul i32 %loadB, %loadA
%add = add nuw nsw i64 %ind, 1
%arrayidxA_plus_4 = getelementptr inbounds i32, i32* %a, i64 %add
store i32 %mulA, i32* %arrayidxA_plus_4, align 4
%arrayidxD = getelementptr inbounds i32, i32* %d, i64 %ind
%loadD = load i32, i32* %arrayidxD, align 4
%arrayidxE = getelementptr inbounds i32, i32* %e, i64 %ind
%loadE = load i32, i32* %arrayidxE, align 4
%mulC = mul i32 %loadD, %loadE
%arrayidxC = getelementptr inbounds i32, i32* %c, i64 %ind
store i32 %mulC, i32* %arrayidxC, align 4
%exitcond = icmp eq i64 %add, 20
br i1 %exitcond, label %for.end, label %for.body, !llvm.loop !2
for.end: ; preds = %for.body
ret void
}
; CHECK-LABEL: @default_distribute(
define void @default_distribute(i32* noalias %a,
i32* noalias %b,
i32* noalias %c,
i32* noalias %d,
i32* noalias %e) {
entry:
br label %for.body
; Verify the two distributed loops.
; DEFAULT_ON: for.body.ldist1:
; DEFAULT_OFF-NOT: for.body.ldist1:
for.body: ; preds = %for.body, %entry
%ind = phi i64 [ 0, %entry ], [ %add, %for.body ]
%arrayidxA = getelementptr inbounds i32, i32* %a, i64 %ind
%loadA = load i32, i32* %arrayidxA, align 4
%arrayidxB = getelementptr inbounds i32, i32* %b, i64 %ind
%loadB = load i32, i32* %arrayidxB, align 4
%mulA = mul i32 %loadB, %loadA
%add = add nuw nsw i64 %ind, 1
%arrayidxA_plus_4 = getelementptr inbounds i32, i32* %a, i64 %add
store i32 %mulA, i32* %arrayidxA_plus_4, align 4
%arrayidxD = getelementptr inbounds i32, i32* %d, i64 %ind
%loadD = load i32, i32* %arrayidxD, align 4
%arrayidxE = getelementptr inbounds i32, i32* %e, i64 %ind
%loadE = load i32, i32* %arrayidxE, align 4
%mulC = mul i32 %loadD, %loadE
%arrayidxC = getelementptr inbounds i32, i32* %c, i64 %ind
store i32 %mulC, i32* %arrayidxC, align 4
%exitcond = icmp eq i64 %add, 20
br i1 %exitcond, label %for.end, label %for.body
for.end: ; preds = %for.body
ret void
}
!0 = distinct !{!0, !1}
!1 = !{!"llvm.loop.distribute.enable", i1 true}
!2 = distinct !{!2, !3}
!3 = !{!"llvm.loop.distribute.enable", i1 false}