The atomic.cmp.swap promotion logic is wrong: it

simply does the atomic.cmp.swap on the larger type,
which means it blows away whatever is sitting in
the bytes just after the memory location, i.e.
causes a buffer overflow.  This really requires
target specific code, which is why LegalizeTypes
doesn't try to handle this case generically.  The
existing (wrong) code in LegalizeDAG will go away
automatically once the type legalization code is
removed from LegalizeDAG so I'm leaving it there
for the moment.  Meanwhile, don't test for this
feature.

llvm-svn: 53669
This commit is contained in:
Duncan Sands 2008-07-16 08:09:48 +00:00
parent 7da34d050b
commit a0b1ab3c0b
1 changed files with 2 additions and 8 deletions

View File

@ -1,5 +1,5 @@
; RUN: llvm-as < %s | llc -march=ppc32 | grep lwarx | count 4
; RUN: llvm-as < %s | llc -march=ppc32 | grep stwcx. | count 4
; RUN: llvm-as < %s | llc -march=ppc32 | grep lwarx | count 3
; RUN: llvm-as < %s | llc -march=ppc32 | grep stwcx. | count 3
define i32 @exchange_and_add(i32* %mem, i32 %val) nounwind {
%tmp = call i32 @llvm.atomic.load.add.i32( i32* %mem, i32 %val )
@ -11,11 +11,6 @@ define i32 @exchange_and_cmp(i32* %mem) nounwind {
ret i32 %tmp
}
define i16 @exchange_and_cmp16(i16* %mem) nounwind {
%tmp = call i16 @llvm.atomic.cmp.swap.i16( i16* %mem, i16 0, i16 1 )
ret i16 %tmp
}
define i32 @exchange(i32* %mem, i32 %val) nounwind {
%tmp = call i32 @llvm.atomic.swap.i32( i32* %mem, i32 1 )
ret i32 %tmp
@ -23,5 +18,4 @@ define i32 @exchange(i32* %mem, i32 %val) nounwind {
declare i32 @llvm.atomic.load.add.i32(i32*, i32) nounwind
declare i32 @llvm.atomic.cmp.swap.i32(i32*, i32, i32) nounwind
declare i16 @llvm.atomic.cmp.swap.i16(i16*, i16, i16) nounwind
declare i32 @llvm.atomic.swap.i32(i32*, i32) nounwind