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The original issue has been fixed by not doing unnecessary sign extensions.

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Change the test to force a sign extension and expose the problem again.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129011 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Rafael Espindola 2011-04-06 17:19:35 +00:00
parent f3480a8015
commit 8617897aaa
1 changed files with 17 additions and 14 deletions
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31
lib/Target/X86/README.txt
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@ -1656,23 +1656,26 @@ information to add the "lock" prefix.
//===---------------------------------------------------------------------===//
_Bool bar(int *x) { return *x & 1; }
struct B {
unsigned char y0 : 1;
};
define zeroext i1 @bar(i32* nocapture %x) nounwind readonly {
entry:
%tmp1 = load i32* %x ; <i32> [#uses=1]
%and = and i32 %tmp1, 1 ; <i32> [#uses=1]
%tobool = icmp ne i32 %and, 0 ; <i1> [#uses=1]
ret i1 %tobool
int bar(struct B* a) { return a->y0; }
define i32 @bar(%struct.B* nocapture %a) nounwind readonly optsize {
%1 = getelementptr inbounds %struct.B* %a, i64 0, i32 0
%2 = load i8* %1, align 1
%3 = and i8 %2, 1
%4 = zext i8 %3 to i32
ret i32 %4
}
bar: # @bar
# BB#0: # %entry
movl 4(%esp), %eax
movb (%eax), %al
andb $1, %al
movzbl %al, %eax
ret
bar: # @bar
# BB#0:
movb (%rdi), %al
andb $1, %al
movzbl %al, %eax
ret
Missed optimization: should be movl+andl.