------- Comment #7 from aldot at gcc dot gnu dot org 2009-06-04 18:18 -------
(In reply to comment #5)
> movzbl 18(%esp), %eax
>
> could be used in this particular case.
4.3.3 onward seem to do that. Fixed?
$ for i in 4.2 4.3 4.4 4.5.orig-HEAD;do printf "### %s\n" $(gcc-$i
-dumpversion) ; gcc-$i -march=i386 -O2 -S -o- pr24929.c -fomit-frame-pointer |
awk 'BEGIN{yep=0;}/^f:/{yep=1;}/^\./{yep=0;}{if (yep){print $0}}';done
### 4.2.4
f:
pushl %edi
pushl %esi
pushl %ebx
movl 16(%esp), %esi
movl 20(%esp), %edi
movl 24(%esp), %ecx
movl 28(%esp), %ebx
movl %ebx, %ecx
xorl %ebx, %ebx
shrl $16, %ecx
movzbl %cl,%eax
xorl %edx, %edx
shldl $8, %esi, %edi
sall $8, %esi
orl %esi, %eax
orl %edi, %edx
popl %ebx
popl %esi
popl %edi
ret
.size f, .-f
.p2align 2,,3
### 4.3.3
f:
movl 4(%esp), %edx
movl 8(%esp), %ecx
shldl $8, %edx, %ecx
sall $8, %edx
movzbl 18(%esp), %eax
orl %edx, %eax
movl %ecx, %edx
ret
.size f, .-f
.p2align 2,,3
### 4.4.0
f:
movl 4(%esp), %edx
movl 8(%esp), %ecx
shldl $8, %edx, %ecx
sall $8, %edx
movzbl 18(%esp), %eax
orl %edx, %eax
movl %ecx, %edx
ret
.size f, .-f
.p2align 2,,3
### 4.5.0
f:
movl 4(%esp), %edx
movl 8(%esp), %ecx
shldl $8, %edx, %ecx
sall $8, %edx
movzbl 18(%esp), %eax
orl %edx, %eax
movl %ecx, %edx
ret
.size f, .-f
.p2align 2,,3
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24929
