If a target zero or sign extends the result of its setcc, allow folding of
this into sign/zero extension instructions later.
On PPC, for example, this testcase:
%G = external global sbyte
implementation
void %test(int %X, int %Y) {
%C = setlt int %X, %Y
%D = cast bool %C to sbyte
store sbyte %D, sbyte* %G
ret void
}
Now codegens to:
cmpw cr0, r3, r4
li r3, 1
li r4, 0
blt .LBB_test_2 ;
.LBB_test_1: ;
or r3, r4, r4
.LBB_test_2: ;
addis r2, r2, ha16(L_G$non_lazy_ptr-"L00000$pb")
lwz r2, lo16(L_G$non_lazy_ptr-"L00000$pb")(r2)
stb r3, 0(r2)
instead of:
cmpw cr0, r3, r4
li r3, 1
li r4, 0
blt .LBB_test_2 ;
.LBB_test_1: ;
or r3, r4, r4
.LBB_test_2: ;
*** rlwinm r3, r3, 0, 31, 31
addis r2, r2, ha16(L_G$non_lazy_ptr-"L00000$pb")
lwz r2, lo16(L_G$non_lazy_ptr-"L00000$pb")(r2)
stb r3, 0(r2)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@21148 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed