From f7be7f15c1ff2882719f823fbe270e48bb0f4340 Mon Sep 17 00:00:00 2001
From: Tyler Nowicki <tnowicki@apple.com>
Date: Thu, 31 Jul 2014 21:22:22 +0000
Subject: [PATCH] Improve the remark generated for -Rpass-missed.

The current remark is ambiguous and makes it sounds like explicitly specifying vectorization will allow the loop to be vectorized. This is not the case. The improved remark directs the user to -Rpass-analysis=loop-vectorize to determine the cause of the pass-miss.

Reviewed by Arnold Schwaighofer`


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214445 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/Vectorize/LoopVectorize.cpp    | 30 ++++++++-----------
 .../X86/vectorization-remarks-missed.ll       |  4 +--
 test/Transforms/LoopVectorize/control-flow.ll |  2 +-
 test/Transforms/LoopVectorize/no_switch.ll    |  2 +-
 4 files changed, 17 insertions(+), 21 deletions(-)

diff --git a/lib/Transforms/Vectorize/LoopVectorize.cpp b/lib/Transforms/Vectorize/LoopVectorize.cpp
index 2cde0871bc4..9daee603f3b 100644
--- a/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -1021,24 +1021,20 @@ public:
 
   std::string emitRemark() const {
     Report R;
-    R << "vectorization ";
-    switch (Force) {
-    case LoopVectorizeHints::FK_Disabled:
-      R << "is explicitly disabled";
-      break;
-    case LoopVectorizeHints::FK_Enabled:
-      R << "is explicitly enabled";
-      if (Width != 0 && Unroll != 0)
-        R << " with width " << Width << " and interleave count " << Unroll;
-      else if (Width != 0)
-        R << " with width " << Width;
-      else if (Unroll != 0)
-        R << " with interleave count " << Unroll;
-      break;
-    case LoopVectorizeHints::FK_Undefined:
-      R << "was not specified";
-      break;
+    if (Force == LoopVectorizeHints::FK_Disabled)
+      R << "vectorization is explicitly disabled";
+    else {
+      R << "use -Rpass-analysis=loop-vectorize for more info";
+      if (Force == LoopVectorizeHints::FK_Enabled) {
+        R << " (Force=true";
+        if (Width != 0)
+          R << ", Vector Width=" << Width;
+        if (Unroll != 0)
+          R << ", Interleave Count=" << Unroll;
+        R << ")";
+      }
     }
+
     return R.str();
   }
 
diff --git a/test/Transforms/LoopVectorize/X86/vectorization-remarks-missed.ll b/test/Transforms/LoopVectorize/X86/vectorization-remarks-missed.ll
index 93f24cbf490..ee21bba6049 100644
--- a/test/Transforms/LoopVectorize/X86/vectorization-remarks-missed.ll
+++ b/test/Transforms/LoopVectorize/X86/vectorization-remarks-missed.ll
@@ -24,10 +24,10 @@
 
 ; File, line, and column should match those specified in the metadata
 ; CHECK: remark: source.cpp:4:5: loop not vectorized: could not determine number of loop iterations
-; CHECK: remark: source.cpp:4:5: loop not vectorized: vectorization was not specified
+; CHECK: remark: source.cpp:4:5: loop not vectorized: use -Rpass-analysis=loop-vectorize for more info
 ; CHECK: remark: source.cpp:13:5: loop not vectorized: vector width and interleave count are explicitly set to 1
 ; CHECK: remark: source.cpp:19:5: loop not vectorized: cannot identify array bounds
-; CHECK: remark: source.cpp:19:5: loop not vectorized: vectorization is explicitly enabled
+; CHECK: remark: source.cpp:19:5: loop not vectorized: use -Rpass-analysis=loop-vectorize for more info
 ; CHECK: warning: source.cpp:19:5: loop not vectorized: failed explicitly specified loop vectorization
 
 ; CHECK: _Z4testPii
diff --git a/test/Transforms/LoopVectorize/control-flow.ll b/test/Transforms/LoopVectorize/control-flow.ll
index e4ba77fa3da..ee8fce11d83 100644
--- a/test/Transforms/LoopVectorize/control-flow.ll
+++ b/test/Transforms/LoopVectorize/control-flow.ll
@@ -11,7 +11,7 @@
 ; }
 
 ; CHECK: remark: source.cpp:5:9: loop not vectorized: loop control flow is not understood by vectorizer
-; CHECK: remark: source.cpp:5:9: loop not vectorized: vectorization was not specified
+; CHECK: remark: source.cpp:5:9: loop not vectorized: use -Rpass-analysis=loop-vectorize for more info
 
 ; CHECK: _Z4testPii
 ; CHECK-NOT: x i32>
diff --git a/test/Transforms/LoopVectorize/no_switch.ll b/test/Transforms/LoopVectorize/no_switch.ll
index 8f654e41d4c..1f1efaffafc 100644
--- a/test/Transforms/LoopVectorize/no_switch.ll
+++ b/test/Transforms/LoopVectorize/no_switch.ll
@@ -1,7 +1,7 @@
 ; RUN: opt < %s -loop-vectorize -force-vector-width=4 -S -pass-remarks-missed='loop-vectorize' -pass-remarks-analysis='loop-vectorize' 2>&1 | FileCheck %s
 
 ; CHECK: remark: source.cpp:4:5: loop not vectorized: loop contains a switch statement
-; CHECK: remark: source.cpp:4:5: loop not vectorized: vectorization is explicitly enabled with width 4
+; CHECK: remark: source.cpp:4:5: loop not vectorized: use -Rpass-analysis=loop-vectorize for more info (Force=true, Vector Width=4)
 ; CHECK: warning: source.cpp:4:5: loop not vectorized: failed explicitly specified loop vectorization
 
 ; CHECK: _Z11test_switchPii
-- 
2.34.1