[llvm] r229064 - [unroll] Concede defeat and disable the unroll analyzer for now.

[Chandler Carruth]

Author: chandlerc
Date: Thu Feb 12 23:31:46 2015
New Revision: 229064

URL: http://llvm.org/viewvc/llvm-project?rev=229064&view=rev
Log:
[unroll] Concede defeat and disable the unroll analyzer for now.

The issues with the new unroll analyzer are more fundamental than code
cleanup, algorithm, or data structure changes. I've sent an email to the
original commit thread with details and a proposal for how to redesign
things. I'm disabling this for now so that we don't spend time
debugging issues with it in its current state.

Modified:
    llvm/trunk/lib/Transforms/Scalar/LoopUnrollPass.cpp
    llvm/trunk/test/Transforms/LoopUnroll/full-unroll-heuristics.ll

Modified: llvm/trunk/lib/Transforms/Scalar/LoopUnrollPass.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LoopUnrollPass.cpp?rev=229064&r1=229063&r2=229064&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/LoopUnrollPass.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/LoopUnrollPass.cpp Thu Feb 12 23:31:46 2015
@@ -42,7 +42,7 @@ UnrollThreshold("unroll-threshold", cl::
   cl::desc("The cut-off point for automatic loop unrolling"));
 
 static cl::opt<unsigned> UnrollMaxIterationsCountToAnalyze(
-    "unroll-max-iteration-count-to-analyze", cl::init(1000), cl::Hidden,
+    "unroll-max-iteration-count-to-analyze", cl::init(0), cl::Hidden,
     cl::desc("Don't allow loop unrolling to simulate more than this number of"
              "iterations when checking full unroll profitability"));
 

Modified: llvm/trunk/test/Transforms/LoopUnroll/full-unroll-heuristics.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopUnroll/full-unroll-heuristics.ll?rev=229064&r1=229063&r2=229064&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/LoopUnroll/full-unroll-heuristics.ll (original)
+++ llvm/trunk/test/Transforms/LoopUnroll/full-unroll-heuristics.ll Thu Feb 12 23:31:46 2015
@@ -17,10 +17,10 @@
 ; optimizations to remove ~55% of the instructions, the loop body size is 9,
 ; and unrolled size is 65.
 
-; RUN: opt < %s -S -loop-unroll -unroll-absolute-threshold=10  -unroll-threshold=10  -unroll-percent-of-optimized-for-complete-unroll=30 | FileCheck %s -check-prefix=TEST1
-; RUN: opt < %s -S -loop-unroll -unroll-absolute-threshold=100 -unroll-threshold=10  -unroll-percent-of-optimized-for-complete-unroll=30 | FileCheck %s -check-prefix=TEST2
-; RUN: opt < %s -S -loop-unroll -unroll-absolute-threshold=100 -unroll-threshold=10  -unroll-percent-of-optimized-for-complete-unroll=80 | FileCheck %s -check-prefix=TEST3
-; RUN: opt < %s -S -loop-unroll -unroll-absolute-threshold=100 -unroll-threshold=100 -unroll-percent-of-optimized-for-complete-unroll=80 | FileCheck %s -check-prefix=TEST4
+; RUN: opt < %s -S -loop-unroll -unroll-max-iteration-count-to-analyze=1000 -unroll-absolute-threshold=10  -unroll-threshold=10  -unroll-percent-of-optimized-for-complete-unroll=30 | FileCheck %s -check-prefix=TEST1
+; RUN: opt < %s -S -loop-unroll -unroll-max-iteration-count-to-analyze=1000 -unroll-absolute-threshold=100 -unroll-threshold=10  -unroll-percent-of-optimized-for-complete-unroll=30 | FileCheck %s -check-prefix=TEST2
+; RUN: opt < %s -S -loop-unroll -unroll-max-iteration-count-to-analyze=1000 -unroll-absolute-threshold=100 -unroll-threshold=10  -unroll-percent-of-optimized-for-complete-unroll=80 | FileCheck %s -check-prefix=TEST3
+; RUN: opt < %s -S -loop-unroll -unroll-max-iteration-count-to-analyze=1000 -unroll-absolute-threshold=100 -unroll-threshold=100 -unroll-percent-of-optimized-for-complete-unroll=80 | FileCheck %s -check-prefix=TEST4
 
 ; If the absolute threshold is too low, or if we can't optimize away requested
 ; percent of instructions, we shouldn't unroll: