commit c27ff0d32db8662c8b1c0ab4ea611bc541fdb19f
author Hiroshi Yamauchi <yamauchi@google.com> Fri Apr 12 15:05:46 2019 +0000
committer Hiroshi Yamauchi <yamauchi@google.com> Fri Apr 12 15:05:46 2019 +0000
tree aa7958030de8f99ee436ea3a99a9b06783d621cb
parent 6c8f4ada360d8d289dbba7c80eb8a1fae991d7d0

Add options for MaxLoadsPerMemcmp(OptSize).

Reviewers: davidxl

Reviewed By: davidxl

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60587

llvm-svn: 358287

llvm/lib/CodeGen/ExpandMemCmp.cpp

diff --git a/llvm/lib/CodeGen/ExpandMemCmp.cpp b/llvm/lib/CodeGen/ExpandMemCmp.cpp
index 6c80c17..a3a9790 100644
--- a/llvm/lib/CodeGen/ExpandMemCmp.cpp
+++ b/llvm/lib/CodeGen/ExpandMemCmp.cpp
@@ -36,6 +36,14 @@
     cl::desc("The number of loads per basic block for inline expansion of "
              "memcmp that is only being compared against zero."));
 
+static cl::opt<unsigned> MaxLoadsPerMemcmp(
+    "max-loads-per-memcmp", cl::Hidden,
+    cl::desc("Set maximum number of loads used in expanded memcmp"));
+
+static cl::opt<unsigned> MaxLoadsPerMemcmpOptSize(
+    "max-loads-per-memcmp-opt-size", cl::Hidden,
+    cl::desc("Set maximum number of loads used in expanded memcmp for -Os/Oz"));
+
 namespace {
 
 
@@ -741,8 +749,13 @@
   const auto *const Options = TTI->enableMemCmpExpansion(IsUsedForZeroCmp);
   if (!Options) return false;
 
-  const unsigned MaxNumLoads =
-      TLI->getMaxExpandSizeMemcmp(CI->getFunction()->hasOptSize());
+  const unsigned MaxNumLoads = CI->getFunction()->hasOptSize()
+      ? (MaxLoadsPerMemcmpOptSize.getNumOccurrences()
+         ? MaxLoadsPerMemcmpOptSize
+         : TLI->getMaxExpandSizeMemcmp(true))
+      : (MaxLoadsPerMemcmp.getNumOccurrences()
+         ? MaxLoadsPerMemcmp
+         : TLI->getMaxExpandSizeMemcmp(false));
 
   unsigned NumLoadsPerBlock = MemCmpEqZeroNumLoadsPerBlock.getNumOccurrences()
                                   ? MemCmpEqZeroNumLoadsPerBlock