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mips.c (override_options): Set MASK_BRANCHLIKELY in target_flags based on ISA...

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2002-08-06  Chris Demetriou  <cgd@broadcom.com>

        * config/mips/mips.c (override_options): Set MASK_BRANCHLIKELY
        in target_flags based on ISA, if it was not set on the command
        line.  Warn if MASK_BRANCHLIKLEY is set but the ISA does not
        support Branch Likely instructions.
        * config/mips/mips.h (MASK_BRANCHLIKLEY): New macro.
        (TARGET_BRANCHLIKELY): Likewise.
        (TARGET_SWITCHES): Add -mbranch-likely and -mno-branch-likely.
        (GENERATE_BRANCHLIKELY): Use TARGET_BRANCHLIKELY rather than
        ISA_HAS_BRANCHLIKELY.
        (ISA_HAS_BRANCHLIKELY): Do not include MIPS16 check.
        * doc/invoke.texi: Document new MIPS -mbranch-likely and
        -mno-branch-likely options.

From-SVN: r56088
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Chris Demetriou 2002-08-07 02:57:53 +00:00 committed by Chris Demetriou
parent f538618eff
commit af34e51e35
4 changed files with 64 additions and 4 deletions
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15
gcc/ChangeLog
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@ -1,3 +1,18 @@
2002-08-06 Chris Demetriou <cgd@broadcom.com>
* config/mips/mips.c (override_options): Set MASK_BRANCHLIKELY
in target_flags based on ISA, if it was not set on the command
line. Warn if MASK_BRANCHLIKLEY is set but the ISA does not
support Branch Likely instructions.
* config/mips/mips.h (MASK_BRANCHLIKLEY): New macro.
(TARGET_BRANCHLIKELY): Likewise.
(TARGET_SWITCHES): Add -mbranch-likely and -mno-branch-likely.
(GENERATE_BRANCHLIKELY): Use TARGET_BRANCHLIKELY rather than
ISA_HAS_BRANCHLIKELY.
(ISA_HAS_BRANCHLIKELY): Do not include MIPS16 check.
* doc/invoke.texi: Document new MIPS -mbranch-likely and
-mno-branch-likely options.
2002-08-06 Kaveh R. Ghazi <ghazi@caip.rutgers.edu>
* ip2k.c (ip2k_set_compare): Add missing iteration variable.

25
gcc/config/mips/mips.c
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@ -5177,6 +5177,31 @@ override_options ()
if (mips_abi != ABI_32 && mips_abi != ABI_O64)
flag_pcc_struct_return = 0;
if ((target_flags_explicit & MASK_BRANCHLIKELY) == 0)
{
/* If neither -mbranch-likely nor -mno-branch-likely was given
on the command line, set MASK_BRANCHLIKELY based on the target
architecture.
By default, we enable use of Branch Likely instructions on
all architectures which support them except for MIPS32 and MIPS64
(i.e., the generic MIPS32 and MIPS64 ISAs, and processors which
implement them).
The MIPS32 and MIPS64 architecture specifications say "Software
is strongly encouraged to avoid use of Branch Likely
instructions, as they will be removed from a future revision
of the [MIPS32 and MIPS64] architecture." Therefore, we do not
issue those instructions unless instructed to do so by
-mbranch-likely. */
if (ISA_HAS_BRANCHLIKELY && !(ISA_MIPS32 || ISA_MIPS64))
target_flags |= MASK_BRANCHLIKELY;
else
target_flags &= ~MASK_BRANCHLIKELY;
}
if (TARGET_BRANCHLIKELY && !ISA_HAS_BRANCHLIKELY)
warning ("generation of Branch Likely instructions enabled, but not supported by architecture");
/* -fpic (-KPIC) is the default when TARGET_ABICALLS is defined. We need
to set flag_pic so that the LEGITIMATE_PIC_OPERAND_P macro will work. */
/* ??? -non_shared turns off pic code generation, but this is not

13
gcc/config/mips/mips.h
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@ -232,6 +232,8 @@ extern void sbss_section PARAMS ((void));
consts in rodata */
#define MASK_NO_FUSED_MADD 0x01000000 /* Don't generate floating point
multiply-add operations. */
#define MASK_BRANCHLIKELY 0x02000000 /* Generate Branch Likely
instructions. */
/* Debug switches, not documented */
#define MASK_DEBUG 0 /* unused */
@ -322,6 +324,8 @@ extern void sbss_section PARAMS ((void));
#define TARGET_NO_CHECK_ZERO_DIV (target_flags & MASK_NO_CHECK_ZERO_DIV)
#define TARGET_CHECK_RANGE_DIV (target_flags & MASK_CHECK_RANGE_DIV)
#define TARGET_BRANCHLIKELY (target_flags & MASK_BRANCHLIKELY)
/* This is true if we must enable the assembly language file switching
code. */
@ -608,6 +612,10 @@ extern void sbss_section PARAMS ((void));
N_("Trap on integer divide overflow")}, \
{"no-check-range-division",-MASK_CHECK_RANGE_DIV, \
N_("Don't trap on integer divide overflow")}, \
{ "branch-likely", MASK_BRANCHLIKELY, \
N_("Use Branch Likely instructions, overriding default for arch")}, \
{ "no-branch-likely", -MASK_BRANCHLIKELY, \
N_("Don't use Branch Likely instructions, overriding default for arch")}, \
{"debug", MASK_DEBUG, \
NULL}, \
{"debuga", MASK_DEBUG_A, \
@ -741,7 +749,7 @@ extern void sbss_section PARAMS ((void));
/* This is meant to be redefined in the host dependent files. */
#define SUBTARGET_TARGET_OPTIONS
#define GENERATE_BRANCHLIKELY (!TARGET_MIPS16 && ISA_HAS_BRANCHLIKELY)
#define GENERATE_BRANCHLIKELY (TARGET_BRANCHLIKELY && !TARGET_MIPS16)
/* Generate three-operand multiply instructions for SImode. */
#define GENERATE_MULT3_SI ((TARGET_MIPS3900 \
@ -776,8 +784,7 @@ extern void sbss_section PARAMS ((void));
/* ISA has branch likely instructions (eg. mips2). */
/* Disable branchlikely for tx39 until compare rewrite. They haven't
been generated up to this point. */
#define ISA_HAS_BRANCHLIKELY (!ISA_MIPS1 \
&& !TARGET_MIPS16)
#define ISA_HAS_BRANCHLIKELY (!ISA_MIPS1)
/* ISA has the conditional move instructions introduced in mips4. */
#define ISA_HAS_CONDMOVE ((ISA_MIPS4 \

15
gcc/doc/invoke.texi
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@ -477,7 +477,8 @@ in the following sections.
-m4650 -msingle-float -mmad @gol
-mstats -EL -EB -G @var{num} -nocpp @gol
-mabi=32 -mabi=n32 -mabi=64 -mabi=eabi @gol
-mfix7000 -mno-crt0 -mflush-func=@var{func} -mno-flush-func}
-mfix7000 -mno-crt0 -mflush-func=@var{func} -mno-flush-func
-mbranch-likely -mno-branch-likely}
@emph{i386 and x86-64 Options}
@gccoptlist{
@ -7369,6 +7370,18 @@ memory range for which the cache is being flushed, the size of the
memory range, and the number 3 (to flush both caches). The default
depends on the target gcc was configured for, but commonly is either
@samp{_flush_func} or @samp{__cpu_flush}.
@item -mbranch-likely
@itemx -mno-branch-likely
@opindex mbranch-likely
@opindex mno-branch-likely
Enable or disable use of Branch Likely instructions, regardless of the
default for the selected architecture. By default, Branch Likely
instructions may be generated if they are supported by the selected
architecture. An exception is for the MIPS32 and MIPS64 architectures
and processors which implement those architectures; for those, Branch
Likely instructions will not be generated by default because the MIPS32
and MIPS64 architectures specifically deprecate their use.
@end table
@node i386 and x86-64 Options