[Bug middle-end/24929] long long shift/mask operations should be better optimized

["aldot at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org>]

------- 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


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24929