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[Bug target/70321] New: [6 Regression] STV generates less optimized code
- From: "hjl.tools at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Sun, 20 Mar 2016 14:40:52 +0000
- Subject: [Bug target/70321] New: [6 Regression] STV generates less optimized code
- Auto-submitted: auto-generated
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70321
Bug ID: 70321
Summary: [6 Regression] STV generates less optimized code
Product: gcc
Version: 6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: hjl.tools at gmail dot com
CC: enkovich.gnu at gmail dot com, ubizjak at gmail dot com
Target Milestone: ---
Target: i386
[hjl@gnu-tools-1 bitwise-1]$ cat z.i
void
foo (long long ixi)
{
if (ixi != 14348907)
__builtin_abort ();
}
[hjl@gnu-tools-1 bitwise-1]$ make z.s z1.s
/export/build/gnu/gcc/build-x86_64-linux/gcc/xgcc
-B/export/build/gnu/gcc/build-x86_64-linux/gcc/ -O2 -m32 -S -o z.s z.i
/export/build/gnu/gcc/build-x86_64-linux/gcc/xgcc
-B/export/build/gnu/gcc/build-x86_64-linux/gcc/ -O2 -m32 -mno-stv -S -o z1.s
z.i
[hjl@gnu-tools-1 bitwise-1]$ cat z.s
.file "z.i"
.text
.p2align 4,,15
.globl foo
.type foo, @function
foo:
.LFB0:
.cfi_startproc
subl $12, %esp
.cfi_def_cfa_offset 16
movl 20(%esp), %edx
movl 16(%esp), %eax
xorb $0, %dh
xorl $14348907, %eax
movl %edx, %ecx
orl %eax, %ecx
jne .L5
addl $12, %esp
.cfi_remember_state
.cfi_def_cfa_offset 4
ret
.L5:
.cfi_restore_state
call abort
.cfi_endproc
.LFE0:
.size foo, .-foo
.ident "GCC: (GNU) 6.0.0 20160318 (experimental)"
.section .note.GNU-stack,"",@progbits
[hjl@gnu-tools-1 bitwise-1]$ cat z1.s
.file "z.i"
.text
.p2align 4,,15
.globl foo
.type foo, @function
foo:
.LFB0:
.cfi_startproc
subl $12, %esp
.cfi_def_cfa_offset 16
movl 16(%esp), %eax
xorl $14348907, %eax
orl 20(%esp), %eax
jne .L5
addl $12, %esp
.cfi_remember_state
.cfi_def_cfa_offset 4
ret
.L5:
.cfi_restore_state
call abort
.cfi_endproc
.LFE0:
.size foo, .-foo
.ident "GCC: (GNU) 6.0.0 20160318 (experimental)"
.section .note.GNU-stack,"",@progbits
[hjl@gnu-tools-1 bitwise-1]$
STV generates:
movl 20(%esp), %edx
movl 16(%esp), %eax
xorb $0, %dh
xorl $14348907, %eax
movl %edx, %ecx
orl %eax, %ecx
vs
movl 16(%esp), %eax
xorl $14348907, %eax
orl 20(%esp), %eax