From ea9ef345581a6bdb6da1bd4c30d614f424254c0d Mon Sep 17 00:00:00 2001
From: Michael Kruse <llvm@meinersbur.de>
Date: Fri, 14 Dec 2018 19:45:43 +0000
Subject: [PATCH] [TransformWarning] Do not warn missed transformations in
 optnone functions.

Optimization transformations are intentionally disabled by the 'optnone'
function attribute. Therefore do not warn if transformation metadata is
still present.

Using the legacy pass manager structure, the `skipFunction` method takes
care for the optnone attribute (already called before this patch). For
the new pass manager, there is no equivalent, so we check for the
'optnone' attribute manually.

Differential Revision: https://reviews.llvm.org/D55690

llvm-svn: 349184
---
 .../lib/Transforms/Scalar/WarnMissedTransforms.cpp |  5 +++
 .../Transforms/LoopTransformWarning/optnone.ll     | 50 ++++++++++++++++++++++
 2 files changed, 55 insertions(+)
 create mode 100644 llvm/test/Transforms/LoopTransformWarning/optnone.ll

diff --git a/llvm/lib/Transforms/Scalar/WarnMissedTransforms.cpp b/llvm/lib/Transforms/Scalar/WarnMissedTransforms.cpp
index d06dcee..80f761e 100644
--- a/llvm/lib/Transforms/Scalar/WarnMissedTransforms.cpp
+++ b/llvm/lib/Transforms/Scalar/WarnMissedTransforms.cpp
@@ -91,6 +91,11 @@ static void warnAboutLeftoverTransformations(Function *F, LoopInfo *LI,
 // New pass manager boilerplate
 PreservedAnalyses
 WarnMissedTransformationsPass::run(Function &F, FunctionAnalysisManager &AM) {
+  // Do not warn about not applied transformations if optimizations are
+  // disabled.
+  if (F.hasFnAttribute(Attribute::OptimizeNone))
+    return PreservedAnalyses::all();
+
   auto &ORE = AM.getResult<OptimizationRemarkEmitterAnalysis>(F);
   auto &LI = AM.getResult<LoopAnalysis>(F);
 
diff --git a/llvm/test/Transforms/LoopTransformWarning/optnone.ll b/llvm/test/Transforms/LoopTransformWarning/optnone.ll
new file mode 100644
index 0000000..866dac8
--- /dev/null
+++ b/llvm/test/Transforms/LoopTransformWarning/optnone.ll
@@ -0,0 +1,50 @@
+; Legacy pass manager
+; RUN: opt -transform-warning -disable-output -pass-remarks-missed=transform-warning -pass-remarks-analysis=transform-warning < %s 2>&1 | FileCheck -allow-empty %s
+;
+; New pass manager
+; RUN: opt -passes=transform-warning -disable-output -pass-remarks-missed=transform-warning -pass-remarks-analysis=transform-warning < %s 2>&1 | FileCheck -allow-empty %s
+;
+; Verify that no transformation warnings are emitted for functions with
+; 'optnone' attribute.
+;
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+
+define void @func(i32* nocapture %A, i32* nocapture readonly %B, i32 %Length) #0 {
+entry:
+  %cmp9 = icmp sgt i32 %Length, 0
+  br i1 %cmp9, label %for.body.preheader, label %for.end
+
+for.body.preheader:
+  br label %for.body
+
+for.body:
+  %indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %for.body.preheader ]
+  %arrayidx = getelementptr inbounds i32, i32* %B, i64 %indvars.iv
+  %0 = load i32, i32* %arrayidx, align 4
+  %idxprom1 = sext i32 %0 to i64
+  %arrayidx2 = getelementptr inbounds i32, i32* %A, i64 %idxprom1
+  %1 = load i32, i32* %arrayidx2, align 4
+  %arrayidx4 = getelementptr inbounds i32, i32* %A, i64 %indvars.iv
+  store i32 %1, i32* %arrayidx4, align 4
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+  %lftr.wideiv = trunc i64 %indvars.iv.next to i32
+  %exitcond = icmp eq i32 %lftr.wideiv, %Length
+  br i1 %exitcond, label %for.end.loopexit, label %for.body, !llvm.loop !0
+
+for.end.loopexit:
+  br label %for.end
+
+for.end:
+  ret void
+}
+
+attributes #0 = { noinline optnone }
+
+!0 = distinct !{!0, !1, !2, !3}
+!1 = !{!"llvm.loop.unroll.enable"}
+!2 = !{!"llvm.loop.distribute.enable"}
+!3 = !{!"llvm.loop.unroll_and_jam.enable"}
+!4 = !{!"llvm.loop.vectorize.enable", i1 true}
+
+
+; CHECK-NOT: warning
-- 
2.7.4