mirror of
https://github.com/gcc-mirror/gcc.git
synced 2026-05-06 14:59:39 +02:00
efb0fdf9f1
Allow QImode subregs of AND results in HImode and SImode (and DImode
on 64-bit targets). Also allow memory operands for the BT base operand
to increase combine opportunities and enable better insn propagation.
The BT insn is slow when using a memory base with a variable bit index,
but the register allocator can reload a memory operand into a register to
satisfy BT pattern constraints.
The patch improves code generation for the included testcase from:
mask_get_flag:
movl %esi, %ecx
movl $1, %eax
salq %cl, %rax
testq %rdi, %rax
setne %al
ret
to:
mask_get_flag:
xorl %eax, %eax
btq %rsi, %rdi
setc %al
ret
gcc/ChangeLog:
* config/i386/i386.md (*bt<SWI48:mode>_mask): Use
int248_register_operand for operand 1 predicate.
(*jcc_bt<mode>_mask): Use nonimmediate_operand for operand 1 predicate.
(*jcc_bt<SWI48:mode>_mask_1): Use nonimmediate_operand for operand 1
predicate and int248_register_operand for operand 2 predicate.
(BT followed by CMOV splitter): Use nonimmediate_operand
for operand 1 predicate.
(*bt<mode>_setcqi): Ditto.
(*bt<mode>_setncqi): Ditto.
(*bt<mode>_setnc<mode>): Ditto.
(*bt<mode>_setncqi_2): Ditto.
(*bt<mode>_setc<mode>_mask): Use nonimmediate_operand for operand 1
predicate and int248_register_operand for operand 2 predicate.
gcc/testsuite/ChangeLog:
* gcc.target/i386/bt-8.c: New test.
This directory contains the GNU Compiler Collection (GCC). The GNU Compiler Collection is free software. See the files whose names start with COPYING for copying permission. The manuals, and some of the runtime libraries, are under different terms; see the individual source files for details. The directory INSTALL contains copies of the installation information as HTML and plain text. The source of this information is gcc/doc/install.texi. The installation information includes details of what is included in the GCC sources and what files GCC installs. See the file gcc/doc/gcc.texi (together with other files that it includes) for usage and porting information. An online readable version of the manual is in the files gcc/doc/gcc.info*. See http://gcc.gnu.org/bugs/ for how to report bugs usefully. Copyright years on GCC source files may be listed using range notation, e.g., 1987-2012, indicating that every year in the range, inclusive, is a copyrightable year that could otherwise be listed individually.