[Bug target/66822] Turn -mtune=iamcu for size

["hjl.tools at gmail dot com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66822

H.J. Lu <hjl.tools at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|Turn off                    |Turn -mtune=iamcu for size
                   |X86_TUNE_ZERO_EXTEND_WITH_A |
                   |ND for -miamcu              |

--- Comment #4 from H.J. Lu <hjl.tools at gmail dot com> ---
-mtune=iamcu should be tuned for size. X86_TUNE_ZERO_EXTEND_WITH_AND
lead to bigger size:

[hjl@gnu-tools-1 pr66822]$ cat x.i
unsigned int
foo (unsigned short x)
{
  return x;
}
[hjl@gnu-tools-1 pr66822]$ /export/build/gnu/gcc/build-x86_64-linux/gcc/xgcc
-B/export/build/gnu/gcc/build-x86_64-linux/gcc/ -O2 -m32 -miamcu -mtune=iamcu
-c -o x.o x.i -mtune-ctrl=^zero_extend_with_and
[hjl@gnu-tools-1 pr66822]$ objdump -dwr x.o

x.o:     file format elf32-i386


Disassembly of section .text:

00000000 <foo>:
   0:   0f b7 c0                movzwl %ax,%eax
   3:   c3                      ret    
[hjl@gnu-tools-1 pr66822]$ /export/build/gnu/gcc/build-x86_64-linux/gcc/xgcc
-B/export/build/gnu/gcc/build-x86_64-linux/gcc/ -O2 -m32 -miamcu -mtune=iamcu
-c -o x.o x.i -mtune-ctrl=zero_extend_with_and
[hjl@gnu-tools-1 pr66822]$ objdump -dwr x.o

x.o:     file format elf32-i386


Disassembly of section .text:

00000000 <foo>:
   0:   25 ff ff 00 00          and    $0xffff,%eax
   5:   c3                      ret    
[hjl@gnu-tools-1 pr66822]$