+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.
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
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 */
#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. */
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, \
/* 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 \
/* 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 \
-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{
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