[PATCH] D29618: Avoid skipping instructions in IndVarSimplify::sinkUnusedInvariants

[Roman Morylev via Phabricator via llvm-commits]

rmorylev created this revision.

Fix a bug when every second instruction wasn't sinked because the iterator was incremented over it


Repository:
  rL LLVM

https://reviews.llvm.org/D29618

Files:
  lib/Transforms/Scalar/IndVarSimplify.cpp
  test/Transforms/IndVarSimplify/exit_value_test3.ll
  test/Transforms/IndVarSimplify/loop_evaluate_1.ll
  test/Transforms/IndVarSimplify/sink-all.ll


Index: test/Transforms/IndVarSimplify/sink-all.ll
===================================================================
--- /dev/null
+++ test/Transforms/IndVarSimplify/sink-all.ll
@@ -0,0 +1,28 @@
+; RUN: opt < %s -indvars -S | FileCheck %s
+
+declare i1 @cond()
+
+define i32 @foo(i32 %x) nounwind {
+entry:
+    %a = mul i32 %x, 2
+    %b = mul i32 %x, 4
+    %c = mul i32 %x, 8
+	br label %for.body
+
+for.body:
+    %cmp = call i1 @cond()
+	br i1 %cmp, label %for.body, label %for.end
+
+for.end:
+    %d = add i32 %a, %b
+    %e = add i32 %c, %d
+	ret i32 %e
+}
+
+; CHECK: for.end:
+; CHECK: mul
+; CHECK: mul
+; CHECK: mul
+; CHECK: add
+; CHECK: add
+; CHECK: ret
Index: test/Transforms/IndVarSimplify/loop_evaluate_1.ll
===================================================================
--- test/Transforms/IndVarSimplify/loop_evaluate_1.ll
+++ test/Transforms/IndVarSimplify/loop_evaluate_1.ll
@@ -26,7 +26,7 @@
 ; CHECK: [[VAR1:%.+]] = add i32 %arg, -11
 ; CHECK: [[VAR2:%.+]] = lshr i32 [[VAR1]], 1
 ; CHECK: [[VAR3:%.+]] = add i32 [[VAR2]], 1
-; CHECK: [[VAR4:%.+]] = phi i32 [ 0, %bb ], [ [[VAR3]], %bb1.preheader ]
+; CHECK: [[VAR4:%.+]] = phi i32 [ 0, %bb ], [ [[VAR3]], %bb7.loopexit ]
 ; CHECK: ret i32 [[VAR4]]
 define i32 @test2(i32 %arg) {
 bb:
Index: test/Transforms/IndVarSimplify/exit_value_test3.ll
===================================================================
--- test/Transforms/IndVarSimplify/exit_value_test3.ll
+++ test/Transforms/IndVarSimplify/exit_value_test3.ll
@@ -4,8 +4,9 @@
 ; is high because the loop can be deleted after the exit value rewrite.
 ;
 ; CHECK-LABEL: @_Z3fooPKcjj(
+; CHECK: br label %[[LABEL:[a-zA-Z0-9_.]+]]
+; CHECK: [[LABEL]]:
 ; CHECK: udiv
-; CHECK: [[LABEL:^[a-zA-Z0-9_.]+]]:
 ; CHECK-NOT: br {{.*}} [[LABEL]]
 
 define i32 @_Z3fooPKcjj(i8* nocapture readnone %s, i32 %len, i32 %c) #0 {
Index: lib/Transforms/Scalar/IndVarSimplify.cpp
===================================================================
--- lib/Transforms/Scalar/IndVarSimplify.cpp
+++ lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -2356,6 +2356,7 @@
     ToMove->moveBefore(*ExitBlock, InsertPt);
     if (Done) break;
     InsertPt = ToMove->getIterator();
+    ++I; // Do not skip instructions
   }
 }
 


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