IA-64 Options

These are the -m options defined for the Intel IA-64 architecture.

-mbig-endian

Generate code for a big-endian target. This is the default for HP-UX.

-mlittle-endian

Generate code for a little-endian target. This is the default for AIX5 and GNU/Linux.

-mgnu-as, -mno-gnu-as

Generate (or don’t) code for the GNU assembler. This is the default.

-mgnu-ld, -mno-gnu-ld

Generate (or don’t) code for the GNU linker. This is the default.

-mno-pic

Generate code that does not use a global pointer register. The result is not position independent code, and violates the IA-64 ABI.

-mvolatile-asm-stop, -mno-volatile-asm-stop

Generate (or don’t) a stop bit immediately before and after volatile asm statements.

-mregister-names, -mno-register-names

Generate (or don’t) in, loc, and out register names for the stacked registers. This may make assembler output more readable.

-mno-sdata, -msdata

Disable (or enable) optimizations that use the small data section. This may be useful for working around optimizer bugs.

-mconstant-gp

Generate code that uses a single constant global pointer value. This is useful when compiling kernel code.

-mauto-pic

Generate code that is self-relocatable. This implies -mconstant-gp. This is useful when compiling firmware code.

-minline-float-divide-min-latency

Generate code for inline divides of floating-point values using the minimum latency algorithm.

-minline-float-divide-max-throughput

Generate code for inline divides of floating-point values using the maximum throughput algorithm.

-mno-inline-float-divide

Do not generate inline code for divides of floating-point values.

-minline-int-divide-min-latency

Generate code for inline divides of integer values using the minimum latency algorithm.

-minline-int-divide-max-throughput

Generate code for inline divides of integer values using the maximum throughput algorithm.

-mno-inline-int-divide

Do not generate inline code for divides of integer values.

-minline-int-divide

Default setting; overrides -mno-inline-int-divide.

-minline-sqrt-min-latency

Generate code for inline square roots using the minimum latency algorithm.

-minline-sqrt-max-throughput

Generate code for inline square roots using the maximum throughput algorithm.

-mno-inline-sqrt

Do not generate inline code for sqrt.

-mfused-madd, -mno-fused-madd

Do (don’t) generate code that uses the fused multiply/add or multiply/subtract instructions. The default is to use these instructions.

-mno-dwarf2-asm, -mdwarf2-asm

Don’t (or do) generate assembler code for the DWARF line number debugging info. This may be useful when not using the GNU assembler.

-mearly-stop-bits, -mno-early-stop-bits

Allow stop bits to be placed earlier than immediately preceding the instruction that triggered the stop bit. This can improve instruction scheduling, but does not always do so.

-mfixed-range=register-range

Generate code treating the given register range as fixed registers. A fixed register is one that the register allocator cannot use. This is useful when compiling kernel code. A register range is specified as two registers separated by a dash. Multiple register ranges can be specified separated by a comma.

-mtls-size=tls-size

Specify bit size of immediate TLS offsets. Valid values are 14, 22, and 64.

-mtune=cpu-type

Tune the instruction scheduling for a particular CPU, Valid values are itanium, itanium1, merced, itanium2, and mckinley.

-milp32, -mlp64

Generate code for a 32-bit or 64-bit environment. The 32-bit environment sets int, long and pointer to 32 bits. The 64-bit environment sets int to 32 bits and long and pointer to 64 bits. These are HP-UX specific flags.

-mno-sched-br-data-spec, -msched-br-data-spec

(Dis/En)able data speculative scheduling before reload. This results in generation of ld.a instructions and the corresponding check instructions (ld.c / chk.a). The default setting is disabled.

-msched-ar-data-spec, -mno-sched-ar-data-spec

(En/Dis)able data speculative scheduling after reload. This results in generation of ld.a instructions and the corresponding check instructions (ld.c / chk.a). The default setting is enabled.

-mno-sched-control-spec, -msched-control-spec

(Dis/En)able control speculative scheduling. This feature is available only during region scheduling (i.e. before reload). This results in generation of the ld.s instructions and the corresponding check instructions chk.s. The default setting is disabled.

-msched-br-in-data-spec, -mno-sched-br-in-data-spec

(En/Dis)able speculative scheduling of the instructions that are dependent on the data speculative loads before reload. This is effective only with -msched-br-data-spec enabled. The default setting is enabled.

-msched-ar-in-data-spec, -mno-sched-ar-in-data-spec

(En/Dis)able speculative scheduling of the instructions that are dependent on the data speculative loads after reload. This is effective only with -msched-ar-data-spec enabled. The default setting is enabled.

-msched-in-control-spec, -mno-sched-in-control-spec

(En/Dis)able speculative scheduling of the instructions that are dependent on the control speculative loads. This is effective only with -msched-control-spec enabled. The default setting is enabled.

-mno-sched-prefer-non-data-spec-insns, -msched-prefer-non-data-spec-insns

If enabled, data-speculative instructions are chosen for schedule only if there are no other choices at the moment. This makes the use of the data speculation much more conservative. The default setting is disabled.

-mno-sched-prefer-non-control-spec-insns, -msched-prefer-non-control-spec-insns

If enabled, control-speculative instructions are chosen for schedule only if there are no other choices at the moment. This makes the use of the control speculation much more conservative. The default setting is disabled.

-mno-sched-count-spec-in-critical-path, -msched-count-spec-in-critical-path

If enabled, speculative dependencies are considered during computation of the instructions priorities. This makes the use of the speculation a bit more conservative. The default setting is disabled.

-msched-spec-ldc

Use a simple data speculation check. This option is on by default.

-msched-control-spec-ldc

Use a simple check for control speculation. This option is on by default.

-msched-stop-bits-after-every-cycle

Place a stop bit after every cycle when scheduling. This option is on by default.

-msched-fp-mem-deps-zero-cost

Assume that floating-point stores and loads are not likely to cause a conflict when placed into the same instruction group. This option is disabled by default.

-msel-sched-dont-check-control-spec

Generate checks for control speculation in selective scheduling. This flag is disabled by default.

-msched-max-memory-insns=max-insns

Limit on the number of memory insns per instruction group, giving lower priority to subsequent memory insns attempting to schedule in the same instruction group. Frequently useful to prevent cache bank conflicts. The default value is 1.

-msched-max-memory-insns-hard-limit

Makes the limit specified by msched-max-memory-insns a hard limit, disallowing more than that number in an instruction group. Otherwise, the limit is ‘soft’, meaning that non-memory operations are preferred when the limit is reached, but memory operations may still be scheduled.