r374288 - Recommit "[Clang] Pragma vectorize_width() implies vectorize(enable)"

Sjoerd Meijer via cfe-commits cfe-commits at lists.llvm.org
Thu Oct 10 01:27:14 PDT 2019


Author: sjoerdmeijer
Date: Thu Oct 10 01:27:14 2019
New Revision: 374288

URL: http://llvm.org/viewvc/llvm-project?rev=374288&view=rev
Log:
Recommit "[Clang] Pragma vectorize_width() implies vectorize(enable)"

This was further discussed at the llvm dev list:

http://lists.llvm.org/pipermail/llvm-dev/2019-October/135602.html

I think the brief summary of that is that this change is an improvement,
this is the behaviour that we expect and promise in ours docs, and also
as a result there are cases where we now emit diagnostics whereas before
pragmas were silently ignored. Two areas where we can improve: 1) the
diagnostic message itself, and 2) and in some cases (e.g. -Os and -Oz)
the vectoriser is (quite understandably) not triggering.

Original commit message:

Specifying the vectorization width was supposed to implicitly enable
vectorization, except that it wasn't really doing this. It was only
setting the vectorize.width metadata, but not vectorize.enable.

This should fix PR27643.

Modified:
    cfe/trunk/lib/CodeGen/CGLoopInfo.cpp
    cfe/trunk/test/CodeGenCXX/pragma-loop-predicate.cpp
    cfe/trunk/test/CodeGenCXX/pragma-loop.cpp

Modified: cfe/trunk/lib/CodeGen/CGLoopInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGLoopInfo.cpp?rev=374288&r1=374287&r2=374288&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGLoopInfo.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGLoopInfo.cpp Thu Oct 10 01:27:14 2019
@@ -270,6 +270,14 @@ LoopInfo::createLoopVectorizeMetadata(co
 
   // Setting vectorize.width
   if (Attrs.VectorizeWidth > 0) {
+    // This implies vectorize.enable = true, but only add it when it is not
+    // already enabled.
+    if (Attrs.VectorizeEnable != LoopAttributes::Enable)
+      Args.push_back(
+          MDNode::get(Ctx, {MDString::get(Ctx, "llvm.loop.vectorize.enable"),
+                            ConstantAsMetadata::get(ConstantInt::get(
+                                llvm::Type::getInt1Ty(Ctx), 1))}));
+
     Metadata *Vals[] = {
         MDString::get(Ctx, "llvm.loop.vectorize.width"),
         ConstantAsMetadata::get(ConstantInt::get(llvm::Type::getInt32Ty(Ctx),

Modified: cfe/trunk/test/CodeGenCXX/pragma-loop-predicate.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/pragma-loop-predicate.cpp?rev=374288&r1=374287&r2=374288&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/pragma-loop-predicate.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/pragma-loop-predicate.cpp Thu Oct 10 01:27:14 2019
@@ -58,7 +58,6 @@ void test5(int *List, int Length) {
     List[i] = i * 2;
 }
 
-
 // CHECK:      ![[LOOP0]] = distinct !{![[LOOP0]], !3}
 // CHECK-NEXT: !3 = !{!"llvm.loop.vectorize.enable", i1 true}
 
@@ -70,7 +69,7 @@ void test5(int *List, int Length) {
 
 // CHECK-NEXT: ![[LOOP3]] = distinct !{![[LOOP3]], !5, !3}
 
-// CHECK-NEXT: ![[LOOP4]] = distinct !{![[LOOP4]], !10}
+// CHECK-NEXT: ![[LOOP4]] = distinct !{![[LOOP4]], !3, !10}
 // CHECK-NEXT: !10 = !{!"llvm.loop.vectorize.width", i32 1}
 
-// CHECK-NEXT: ![[LOOP5]] = distinct !{![[LOOP5]], !10}
+// CHECK-NEXT: ![[LOOP5]] = distinct !{![[LOOP5]], !3, !10}

Modified: cfe/trunk/test/CodeGenCXX/pragma-loop.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/pragma-loop.cpp?rev=374288&r1=374287&r2=374288&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/pragma-loop.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/pragma-loop.cpp Thu Oct 10 01:27:14 2019
@@ -158,23 +158,41 @@ void template_test(double *List, int Len
   for_template_constant_expression_test<double, 2, 4, 8>(List, Length);
 }
 
+void vec_width_1(int *List, int Length) {
+// CHECK-LABEL: @{{.*}}vec_width_1{{.*}}(
+// CHECK: br label {{.*}}, !llvm.loop ![[LOOP_15:.*]]
+
+  #pragma clang loop vectorize(enable) vectorize_width(1)
+  for (int i = 0; i < Length; i++)
+    List[i] = i * 2;
+}
+
+void width_1(int *List, int Length) {
+// CHECK-LABEL: @{{.*}}width_1{{.*}}(
+// CHECK: br label {{.*}}, !llvm.loop ![[LOOP_16:.*]]
+
+  #pragma clang loop vectorize_width(1)
+  for (int i = 0; i < Length; i++)
+    List[i] = i * 2;
+}
+
 // CHECK: ![[LOOP_1]] = distinct !{![[LOOP_1]], ![[UNROLL_FULL:.*]]}
 // CHECK: ![[UNROLL_FULL]] = !{!"llvm.loop.unroll.full"}
 
-// CHECK: ![[LOOP_2]] = distinct !{![[LOOP_2]], ![[UNROLL_DISABLE:.*]], ![[DISTRIBUTE_DISABLE:.*]], ![[WIDTH_8:.*]], ![[INTERLEAVE_4:.*]]}
+// CHECK: ![[LOOP_2]] = distinct !{![[LOOP_2]], ![[UNROLL_DISABLE:.*]], ![[DISTRIBUTE_DISABLE:.*]], ![[VECTORIZE_ENABLE:.*]], ![[WIDTH_8:.*]], ![[INTERLEAVE_4:.*]]}
 // CHECK: ![[UNROLL_DISABLE]] = !{!"llvm.loop.unroll.disable"}
 // CHECK: ![[DISTRIBUTE_DISABLE]] = !{!"llvm.loop.distribute.enable", i1 false}
+// CHECK: ![[VECTORIZE_ENABLE]] = !{!"llvm.loop.vectorize.enable", i1 true}
 // CHECK: ![[WIDTH_8]] = !{!"llvm.loop.vectorize.width", i32 8}
 // CHECK: ![[INTERLEAVE_4]] = !{!"llvm.loop.interleave.count", i32 4}
 
-// CHECK: ![[LOOP_3]] = distinct !{![[LOOP_3]], ![[INTERLEAVE_4:.*]], ![[INTENABLE_1:.*]], ![[FOLLOWUP_VECTOR_3:.*]]}
-// CHECK: ![[INTENABLE_1]] = !{!"llvm.loop.vectorize.enable", i1 true}
+// CHECK: ![[LOOP_3]] = distinct !{![[LOOP_3]], ![[INTERLEAVE_4:.*]], ![[VECTORIZE_ENABLE]], ![[FOLLOWUP_VECTOR_3:.*]]}
 // CHECK: ![[FOLLOWUP_VECTOR_3]] = !{!"llvm.loop.vectorize.followup_all", ![[AFTER_VECTOR_3:.*]]}
 // CHECK: ![[AFTER_VECTOR_3]] = distinct !{![[AFTER_VECTOR_3]], ![[ISVECTORIZED:.*]], ![[UNROLL_8:.*]]}
 // CHECK: ![[ISVECTORIZED]] = !{!"llvm.loop.isvectorized"}
 // CHECK: ![[UNROLL_8]] = !{!"llvm.loop.unroll.count", i32 8}
 
-// CHECK: ![[LOOP_4]] = distinct !{![[LOOP_4]], ![[WIDTH_2:.*]], ![[INTERLEAVE_2:.*]]}
+// CHECK: ![[LOOP_4]] = distinct !{![[LOOP_4]], ![[VECTORIZE_ENABLE]], ![[WIDTH_2:.*]], ![[INTERLEAVE_2:.*]]}
 // CHECK: ![[WIDTH_2]] = !{!"llvm.loop.vectorize.width", i32 2}
 // CHECK: ![[INTERLEAVE_2]] = !{!"llvm.loop.interleave.count", i32 2}
 
@@ -185,7 +203,7 @@ void template_test(double *List, int Len
 // CHECK: ![[FOLLOWUP_VECTOR_6]] = !{!"llvm.loop.vectorize.followup_all", ![[AFTER_VECTOR_6:.*]]}
 // CHECK: ![[AFTER_VECTOR_6]] = distinct !{![[AFTER_VECTOR_6]], ![[ISVECTORIZED:.*]], ![[UNROLL_8:.*]]}
 
-// CHECK: ![[LOOP_7]] = distinct !{![[LOOP_7]], ![[WIDTH_5:.*]]}
+// CHECK: ![[LOOP_7]] = distinct !{![[LOOP_7]], ![[VECTORIZE_ENABLE]], ![[WIDTH_5:.*]]}
 // CHECK: ![[WIDTH_5]] = !{!"llvm.loop.vectorize.width", i32 5}
 
 // CHECK: ![[LOOP_8]] = distinct !{![[LOOP_8]], ![[WIDTH_5:.*]]}
@@ -213,5 +231,9 @@ void template_test(double *List, int Len
 // CHECK: ![[AFTER_VECTOR_13]] = distinct !{![[AFTER_VECTOR_13]], ![[ISVECTORIZED:.*]], ![[UNROLL_32:.*]]}
 // CHECK: ![[UNROLL_32]] = !{!"llvm.loop.unroll.count", i32 32}
 
-// CHECK: ![[LOOP_14]] = distinct !{![[LOOP_14]], ![[WIDTH_10:.*]]}
+// CHECK: ![[LOOP_14]] = distinct !{![[LOOP_14]], ![[VECTORIZE_ENABLE]], ![[WIDTH_10:.*]]}
 // CHECK: ![[WIDTH_10]] = !{!"llvm.loop.vectorize.width", i32 10}
+
+// CHECK:      ![[LOOP_15]] = distinct !{![[LOOP_15]], ![[WIDTH_1]], ![[VECTORIZE_ENABLE]]}
+
+// CHECK-NEXT: ![[LOOP_16]] = distinct !{![[LOOP_16]], ![[VECTORIZE_ENABLE]], ![[WIDTH_1]]}




More information about the cfe-commits mailing list