From 93c6c7734046ee8fad8a713872caf7ed2ae1f555 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Mon, 21 Sep 2009 02:53:57 +0000 Subject: [PATCH] one case handled, expanded another testcase inline. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82427 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/README.txt | 36 ++++++++++++++++-------------------- 1 file changed, 16 insertions(+), 20 deletions(-) diff --git a/lib/Target/README.txt b/lib/Target/README.txt index b44c5fa9bc3..8ff08fbf036 100644 --- a/lib/Target/README.txt +++ b/lib/Target/README.txt @@ -1268,6 +1268,8 @@ http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35287 [LPRE crit edge splitting] http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34677 (licm does this, LPRE crit edge) llvm-gcc t2.c -S -o - -O0 -emit-llvm | llvm-as | opt -mem2reg -simplifycfg -gvn | llvm-dis +http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16799 [BITCAST PHI TRANS] + //===---------------------------------------------------------------------===// Type based alias analysis: @@ -1275,31 +1277,25 @@ http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14705 //===---------------------------------------------------------------------===// -When GVN/PRE finds a store of float* to a must aliases pointer when expecting -an int*, it should turn it into a bitcast. This is a nice generalization of -the SROA hack that would apply to other cases, e.g.: - -int foo(int C, int *P, float X) { - if (C) { - bar(); - *P = 42; - } else - *(float*)P = X; - - return *P; -} - - -One example (that requires crazy phi translation) is: -http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16799 [BITCAST PHI TRANS] - -//===---------------------------------------------------------------------===// - A/B get pinned to the stack because we turn an if/then into a select instead of PRE'ing the load/store. This may be fixable in instcombine: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37892 +struct X { int i; }; +int foo (int x) { + struct X a; + struct X b; + struct X *p; + a.i = 1; + b.i = 2; + if (x) + p = &a; + else + p = &b; + return p->i; +} +//===---------------------------------------------------------------------===// Interesting missed case because of control flow flattening (should be 2 loads): http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26629