Improve the remark generated when a variable that is used outside the loop is not a reduction or induction variable.

Reviewed by Arnold Schwaighofer

llvm-svn: 214440

2 files changed, 8 insertions, 4 deletions

diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index a88eb490e40..2cde0871bc4 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -3590,8 +3590,8 @@ bool LoopVectorizationLegality::canVectorizeInstrs() {
           // identified reduction value with an outside user.
           if (!hasOutsideLoopUser(TheLoop, it, AllowedExit))
             continue;
-          emitAnalysis(Report(it) << "value that could not be identified as "
-                                     "reduction is used outside the loop");
+          emitAnalysis(Report(it) << "value could not be identified as "
+                                     "an induction or reduction variable");
           return false;
         }
 
@@ -3676,7 +3676,8 @@ bool LoopVectorizationLegality::canVectorizeInstrs() {
           continue;
         }
 
-        emitAnalysis(Report(it) << "unvectorizable operation");
+        emitAnalysis(Report(it) << "value that could not be identified as "
+                                   "reduction is used outside the loop");
         DEBUG(dbgs() << "LV: Found an unidentified PHI."<< *Phi <<"\n");
         return false;
       }// end of PHI handling
diff --git a/llvm/test/Transforms/LoopVectorize/no_outside_user.ll b/llvm/test/Transforms/LoopVectorize/no_outside_user.ll
index 1f891ad2c4f..f6c0c7621b3 100644
--- a/llvm/test/Transforms/LoopVectorize/no_outside_user.ll
+++ b/llvm/test/Transforms/LoopVectorize/no_outside_user.ll
@@ -1,4 +1,7 @@
-; RUN: opt -S -loop-vectorize -force-vector-unroll=1 -force-vector-width=2 < %s | FileCheck %s
+; RUN: opt -S -loop-vectorize -force-vector-unroll=1 -force-vector-width=2 -pass-remarks-analysis=loop-vectorize < %s 2>&1 | FileCheck %s
+
+; CHECK: remark: {{.*}}: loop not vectorized: value could not be identified as an induction or reduction variable
+; CHECK: remark: {{.*}}: loop not vectorized: use of induction value outside of the loop is not handled by vectorizer
 
 target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32-n8:16:32-S128"