[BasicAA] Enable -basic-aa-recphi by default

This option was added a while back, to help improve AA around pointer
phi loops. It looks for phi(gep(phi, const), x) loops, checking if x can
then prove more precise aliasing info.

Differential Revision: https://reviews.llvm.org/D82998

diff --git a/llvm/lib/Analysis/BasicAliasAnalysis.cpp b/llvm/lib/Analysis/BasicAliasAnalysis.cpp
index 7466409..5574d3f 100644 (file)
--- a/llvm/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/llvm/lib/Analysis/BasicAliasAnalysis.cpp
@@ -66,7 +66,7 @@ using namespace llvm;
 
 /// Enable analysis of recursive PHI nodes.
 static cl::opt<bool> EnableRecPhiAnalysis("basic-aa-recphi", cl::Hidden,
-                                          cl::init(false));
+                                          cl::init(true));
 
 /// By default, even on 32-bit architectures we use 64-bit integers for
 /// calculations. This will allow us to more-aggressively decompose indexing

diff --git a/llvm/test/Analysis/BasicAA/phi-loop.ll b/llvm/test/Analysis/BasicAA/phi-loop.ll
index db3023c..e54752a 100644 (file)
--- a/llvm/test/Analysis/BasicAA/phi-loop.ll
+++ b/llvm/test/Analysis/BasicAA/phi-loop.ll
@@ -1,4 +1,4 @@
-; RUN: opt < %s -basic-aa -basic-aa-recphi=1 -gvn -S | FileCheck %s
+; RUN: opt < %s -basic-aa -gvn -S | FileCheck %s
 ;
 ; Check that section->word_ofs doesn't get reloaded in every iteration of the
 ; for loop.

diff --git a/llvm/test/Analysis/BasicAA/recphi.ll b/llvm/test/Analysis/BasicAA/recphi.ll
index 130058c..bdd85c8 100644 (file)
--- a/llvm/test/Analysis/BasicAA/recphi.ll
+++ b/llvm/test/Analysis/BasicAA/recphi.ll
@@ -1,4 +1,4 @@
-; RUN: opt < %s -basic-aa -aa-eval -print-all-alias-modref-info -basic-aa-recphi -disable-output 2>&1 | FileCheck %s
+; RUN: opt < %s -basic-aa -aa-eval -print-all-alias-modref-info -disable-output 2>&1 | FileCheck %s
 
 ; CHECK-LABEL: Function: simple: 5 pointers, 0 call sites
 ; CHECK:         NoAlias:      float* %src1, float* %src2