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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60404 91177308-0d34-0410-b5e6-96231b3b80d8
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Chris Lattner 2008-12-02 06:32:34 +00:00
parent 286a054908
commit 88d84b245c
1 changed files with 21 additions and 0 deletions
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21
lib/Target/README.txt
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@ -1252,3 +1252,24 @@ have the concept of a "C signed subtraction" operator that which is undefined
on overflow.
//===---------------------------------------------------------------------===//
This was noticed in the entryblock for grokdeclarator in 403.gcc:
%tmp = icmp eq i32 %decl_context, 4
%decl_context_addr.0 = select i1 %tmp, i32 3, i32 %decl_context
%tmp1 = icmp eq i32 %decl_context_addr.0, 1
%decl_context_addr.1 = select i1 %tmp1, i32 0, i32 %decl_context_addr.0
tmp1 should be simplified to something like:
(!tmp || decl_context == 1)
This allows recursive simplifications, tmp1 is used all over the place in
the function, e.g. by:
%tmp23 = icmp eq i32 %decl_context_addr.1, 0 ; <i1> [#uses=1]
%tmp24 = xor i1 %tmp1, true ; <i1> [#uses=1]
%or.cond8 = and i1 %tmp23, %tmp24 ; <i1> [#uses=1]
later.