[PATCH] D48721: Patch to fix pragma metadata for do-while loops

Bjorn Pettersson via Phabricator via cfe-commits cfe-commits at lists.llvm.org
Tue Jul 10 13:00:09 PDT 2018


This revision was automatically updated to reflect the committed changes.
Closed by commit rL336717: Patch to fix pragma metadata for do-while loops (authored by bjope, committed by ).
Herald added a subscriber: llvm-commits.

Changed prior to commit:
  https://reviews.llvm.org/D48721?vs=154244&id=154865#toc

Repository:
  rL LLVM

https://reviews.llvm.org/D48721

Files:
  cfe/trunk/lib/CodeGen/CGStmt.cpp
  cfe/trunk/test/CodeGen/pragma-do-while.cpp


Index: cfe/trunk/test/CodeGen/pragma-do-while.cpp
===================================================================
--- cfe/trunk/test/CodeGen/pragma-do-while.cpp
+++ cfe/trunk/test/CodeGen/pragma-do-while.cpp
@@ -0,0 +1,36 @@
+// RUN: %clang_cc1 -emit-llvm %s -o - | FileCheck %s
+
+// We expect to get a loop structure like this:
+//    do.body:                                       ; preds = %do.cond, ...
+//      ...
+//      br label %do.cond
+//    do.cond:                                       ; preds = %do.body
+//      ...
+//      br i1 %cmp, label %do.body, label %do.end
+//    do.end:                                        ; preds = %do.cond
+//      ...
+//
+// Verify that the loop metadata only is put on the backedge.
+//
+// CHECK-NOT: llvm.loop
+// CHECK-LABEL: do.cond:
+// CHECK: br {{.*}}, label %do.body, label %do.end, !llvm.loop ![[LMD1:[0-9]+]]
+// CHECK-LABEL: do.end:
+// CHECK-NOT: llvm.loop
+// CHECK: ![[LMD1]] = distinct !{![[LMD1]], ![[LMD2:[0-9]+]]}
+// CHECK: ![[LMD2]] = !{!"llvm.loop.unroll.count", i32 4}
+
+int test(int a[], int n) {
+  int i = 0;
+  int sum = 0;
+
+#pragma unroll 4
+  do
+  {
+    a[i] = a[i] + 1;
+    sum = sum + a[i];
+    i++;
+  } while (i < n);
+
+  return sum;
+}
Index: cfe/trunk/lib/CodeGen/CGStmt.cpp
===================================================================
--- cfe/trunk/lib/CodeGen/CGStmt.cpp
+++ cfe/trunk/lib/CodeGen/CGStmt.cpp
@@ -777,19 +777,19 @@
   // Emit the body of the loop.
   llvm::BasicBlock *LoopBody = createBasicBlock("do.body");
 
-  const SourceRange &R = S.getSourceRange();
-  LoopStack.push(LoopBody, CGM.getContext(), DoAttrs,
-                 SourceLocToDebugLoc(R.getBegin()),
-                 SourceLocToDebugLoc(R.getEnd()));
-
   EmitBlockWithFallThrough(LoopBody, &S);
   {
     RunCleanupsScope BodyScope(*this);
     EmitStmt(S.getBody());
   }
 
   EmitBlock(LoopCond.getBlock());
 
+  const SourceRange &R = S.getSourceRange();
+  LoopStack.push(LoopBody, CGM.getContext(), DoAttrs,
+                 SourceLocToDebugLoc(R.getBegin()),
+                 SourceLocToDebugLoc(R.getEnd()));
+
   // C99 6.8.5.2: "The evaluation of the controlling expression takes place
   // after each execution of the loop body."
 


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D48721.154865.patch
Type: text/x-patch
Size: 2237 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20180710/994b5aff/attachment.bin>


More information about the cfe-commits mailing list