[llvm] fa5cb4b - [LoopFlatten] Disable IV widening

[Sjoerd Meijer via llvm-commits]

Author: Sjoerd Meijer
Date: 2020-11-16T22:30:52Z
New Revision: fa5cb4b9366228e8e17a95990a021e62376a592f

URL: https://github.com/llvm/llvm-project/commit/fa5cb4b9366228e8e17a95990a021e62376a592f
DIFF: https://github.com/llvm/llvm-project/commit/fa5cb4b9366228e8e17a95990a021e62376a592f.diff

LOG: [LoopFlatten] Disable IV widening

Disable widening of the IV in LoopFlatten while I investigate an assertion
failures. Please note that the pass is also not yet enabled by default.

Added: 
    

Modified: 
    llvm/lib/Transforms/Scalar/LoopFlatten.cpp
    llvm/test/Transforms/LoopFlatten/widen-iv.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/Scalar/LoopFlatten.cpp b/llvm/lib/Transforms/Scalar/LoopFlatten.cpp
index 37531d6301e5..3d9617d43aea 100644
--- a/llvm/lib/Transforms/Scalar/LoopFlatten.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopFlatten.cpp
@@ -66,7 +66,7 @@ static cl::opt<bool>
 
 static cl::opt<bool>
     WidenIV("loop-flatten-widen-iv", cl::Hidden,
-            cl::init(true),
+            cl::init(false),
             cl::desc("Widen the loop induction variables, if possible, so "
                      "overflow checks won't reject flattening"));
 

diff  --git a/llvm/test/Transforms/LoopFlatten/widen-iv.ll b/llvm/test/Transforms/LoopFlatten/widen-iv.ll
index bb3fa3360d0e..579061833bf4 100644
--- a/llvm/test/Transforms/LoopFlatten/widen-iv.ll
+++ b/llvm/test/Transforms/LoopFlatten/widen-iv.ll
@@ -1,5 +1,5 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt < %s -S -loop-flatten -verify-loop-info -verify-dom-info -verify-scev -verify | FileCheck %s --check-prefix=CHECK
+; RUN: opt < %s -S -loop-flatten -loop-flatten-widen-iv=true -verify-loop-info -verify-dom-info -verify-scev -verify | FileCheck %s --check-prefix=CHECK
 ; RUN: opt < %s -S -loop-flatten -loop-flatten-widen-iv=false -verify-loop-info -verify-dom-info -verify-scev -verify | FileCheck %s --check-prefix=DONTWIDEN
 
 target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"