path: root/gcc/config/rs6000/rs6000.opt

; Options for the rs6000 port of the compiler
;
; Copyright (C) 2005-2018 Free Software Foundation, Inc.
; Contributed by Aldy Hernandez <aldy@quesejoda.com>.
;
; This file is part of GCC.
;
; GCC is free software; you can redistribute it and/or modify it under
; the terms of the GNU General Public License as published by the Free
; Software Foundation; either version 3, or (at your option) any later
; version.
;
; GCC is distributed in the hope that it will be useful, but WITHOUT
; ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
; or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
; License for more details.
;
; You should have received a copy of the GNU General Public License
; along with GCC; see the file COPYING3.  If not see
; <http://www.gnu.org/licenses/>.

HeaderInclude
config/rs6000/rs6000-opts.h

;; ISA flag bits (on/off)
Variable
HOST_WIDE_INT rs6000_isa_flags = TARGET_DEFAULT

TargetSave
HOST_WIDE_INT x_rs6000_isa_flags

;; Miscellaneous flag bits that were set explicitly by the user
Variable
HOST_WIDE_INT rs6000_isa_flags_explicit

TargetSave
HOST_WIDE_INT x_rs6000_isa_flags_explicit

;; Current processor
TargetVariable
enum processor_type rs6000_cpu = PROCESSOR_PPC603

;; Current tuning
TargetVariable
enum processor_type rs6000_tune = PROCESSOR_PPC603

;; Always emit branch hint bits.
TargetVariable
unsigned char rs6000_always_hint

;; Schedule instructions for group formation.
TargetVariable
unsigned char rs6000_sched_groups

;; Align branch targets.
TargetVariable
unsigned char rs6000_align_branch_targets

;; Support for -msched-costly-dep option.
TargetVariable
enum rs6000_dependence_cost rs6000_sched_costly_dep = no_dep_costly

;; Support for -minsert-sched-nops option.
TargetVariable
enum rs6000_nop_insertion rs6000_sched_insert_nops = sched_finish_none

;; Non-zero to allow overriding loop alignment.
TargetVariable
unsigned char can_override_loop_align

;; Which small data model to use (for System V targets only)
TargetVariable
enum rs6000_sdata_type rs6000_sdata = SDATA_DATA

;; Bit size of immediate TLS offsets and string from which it is decoded.
TargetVariable
int rs6000_tls_size = 32

;; ABI enumeration available for subtarget to use.
TargetVariable
enum rs6000_abi rs6000_current_abi = ABI_NONE

;; Type of traceback to use.
TargetVariable
enum rs6000_traceback_type rs6000_traceback = traceback_default

;; Control alignment for fields within structures.
TargetVariable
unsigned char rs6000_alignment_flags

;; Code model for 64-bit linux.
TargetVariable
enum rs6000_cmodel rs6000_current_cmodel = CMODEL_SMALL

;; What type of reciprocal estimation instructions to generate
TargetVariable
unsigned int rs6000_recip_control

;; Mask of what builtin functions are allowed
TargetVariable
HOST_WIDE_INT rs6000_builtin_mask

;; Debug flags
TargetVariable
unsigned int rs6000_debug

;; Whether to enable the -mfloat128 stuff without necessarily enabling the
;; __float128 keyword.
TargetSave
unsigned char x_TARGET_FLOAT128_TYPE

Variable
unsigned char TARGET_FLOAT128_TYPE

;; This option existed in the past, but now is always on.
mpowerpc
Target RejectNegative Undocumented Ignore

mpowerpc64
Target Report Mask(POWERPC64) Var(rs6000_isa_flags)
Use PowerPC-64 instruction set.

mpowerpc-gpopt
Target Report Mask(PPC_GPOPT) Var(rs6000_isa_flags)
Use PowerPC General Purpose group optional instructions.

mpowerpc-gfxopt
Target Report Mask(PPC_GFXOPT) Var(rs6000_isa_flags)
Use PowerPC Graphics group optional instructions.

mmfcrf
Target Report Mask(MFCRF) Var(rs6000_isa_flags)
Use PowerPC V2.01 single field mfcr instruction.

mpopcntb
Target Report Mask(POPCNTB) Var(rs6000_isa_flags)
Use PowerPC V2.02 popcntb instruction.

mfprnd
Target Report Mask(FPRND) Var(rs6000_isa_flags)
Use PowerPC V2.02 floating point rounding instructions.

mcmpb
Target Report Mask(CMPB) Var(rs6000_isa_flags)
Use PowerPC V2.05 compare bytes instruction.

mmfpgpr
Target Report Mask(MFPGPR) Var(rs6000_isa_flags)
Use extended PowerPC V2.05 move floating point to/from GPR instructions.

maltivec
Target Report Mask(ALTIVEC) Var(rs6000_isa_flags)
Use AltiVec instructions.

mfold-gimple
Target Report Var(rs6000_fold_gimple) Init(1)
Enable early gimple folding of builtins.

mhard-dfp
Target Report Mask(DFP) Var(rs6000_isa_flags)
Use decimal floating point instructions.

mmulhw
Target Report Mask(MULHW) Var(rs6000_isa_flags)
Use 4xx half-word multiply instructions.

mdlmzb
Target Report Mask(DLMZB) Var(rs6000_isa_flags)
Use 4xx string-search dlmzb instruction.

mmultiple
Target Report Mask(MULTIPLE) Var(rs6000_isa_flags)
Generate load/store multiple instructions.

;; This option existed in the past, but now is always off.
mno-string
Target RejectNegative Undocumented Ignore

mstring
Target RejectNegative Undocumented Deprecated

msoft-float
Target Report RejectNegative Mask(SOFT_FLOAT) Var(rs6000_isa_flags)
Do not use hardware floating point.

mhard-float
Target Report RejectNegative InverseMask(SOFT_FLOAT, HARD_FLOAT) Var(rs6000_isa_flags)
Use hardware floating point.

mpopcntd
Target Report Mask(POPCNTD) Var(rs6000_isa_flags)
Use PowerPC V2.06 popcntd instruction.

mfriz
Target Report Var(TARGET_FRIZ) Init(-1) Save
Under -ffast-math, generate a FRIZ instruction for (double)(long long) conversions.

mveclibabi=
Target RejectNegative Joined Var(rs6000_veclibabi_name)
Vector library ABI to use.

mvsx
Target Report Mask(VSX) Var(rs6000_isa_flags)
Use vector/scalar (VSX) instructions.

mvsx-align-128
Target Undocumented Report Var(TARGET_VSX_ALIGN_128) Save
; If -mvsx, set alignment to 128 bits instead of 32/64

mallow-movmisalign
Target Undocumented Var(TARGET_ALLOW_MOVMISALIGN) Init(-1) Save
; Allow the movmisalign in DF/DI vectors

mefficient-unaligned-vsx
Target Undocumented Report Mask(EFFICIENT_UNALIGNED_VSX) Var(rs6000_isa_flags)
; Consider unaligned VSX vector and fp accesses to be efficient

msched-groups
Target Undocumented Report Var(TARGET_SCHED_GROUPS) Init(-1) Save
; Explicitly set rs6000_sched_groups

malways-hint
Target Undocumented Report Var(TARGET_ALWAYS_HINT) Init(-1) Save
; Explicitly set rs6000_always_hint

malign-branch-targets
Target Undocumented Report Var(TARGET_ALIGN_BRANCH_TARGETS) Init(-1) Save
; Explicitly set rs6000_align_branch_targets

mno-update
Target Report RejectNegative Mask(NO_UPDATE) Var(rs6000_isa_flags)
Do not generate load/store with update instructions.

mupdate
Target Report RejectNegative InverseMask(NO_UPDATE, UPDATE) Var(rs6000_isa_flags)
Generate load/store with update instructions.

msingle-pic-base
Target Report Var(TARGET_SINGLE_PIC_BASE) Init(0)
Do not load the PIC register in function prologues.

mavoid-indexed-addresses
Target Report Var(TARGET_AVOID_XFORM) Init(-1) Save
Avoid generation of indexed load/store instructions when possible.

mtls-markers
Target Report Var(tls_markers) Init(1) Save
Mark __tls_get_addr calls with argument info.

msched-epilog
Target Undocumented Var(TARGET_SCHED_PROLOG) Init(1) Save

msched-prolog
Target Report Var(TARGET_SCHED_PROLOG) Save
Schedule the start and end of the procedure.

maix-struct-return
Target Report RejectNegative Var(aix_struct_return) Save
Return all structures in memory (AIX default).

msvr4-struct-return
Target Report RejectNegative Var(aix_struct_return,0) Save
Return small structures in registers (SVR4 default).

mxl-compat
Target Report Var(TARGET_XL_COMPAT) Save
Conform more closely to IBM XLC semantics.

mrecip
Target Report
Generate software reciprocal divide and square root for better throughput.

mrecip=
Target Report RejectNegative Joined Var(rs6000_recip_name)
Generate software reciprocal divide and square root for better throughput.

mrecip-precision
Target Report Mask(RECIP_PRECISION) Var(rs6000_isa_flags)
Assume that the reciprocal estimate instructions provide more accuracy.

mno-fp-in-toc
Target Report RejectNegative Var(TARGET_NO_FP_IN_TOC) Save
Do not place floating point constants in TOC.

mfp-in-toc
Target Report RejectNegative Var(TARGET_NO_FP_IN_TOC,0) Save
Place floating point constants in TOC.

mno-sum-in-toc
Target RejectNegative Var(TARGET_NO_SUM_IN_TOC) Save
Do not place symbol+offset constants in TOC.

msum-in-toc
Target RejectNegative Var(TARGET_NO_SUM_IN_TOC,0) Save
Place symbol+offset constants in TOC.

;  Output only one TOC entry per module.  Normally linking fails if
;   there are more than 16K unique variables/constants in an executable.  With
;   this option, linking fails only if there are more than 16K modules, or
;   if there are more than 16K unique variables/constant in a single module.
;
;   This is at the cost of having 2 extra loads and one extra store per
;   function, and one less allocable register.
mminimal-toc
Target Report Mask(MINIMAL_TOC) Var(rs6000_isa_flags)
Use only one TOC entry per procedure.

mfull-toc
Target Report
Put everything in the regular TOC.

mvrsave
Target Report Var(TARGET_ALTIVEC_VRSAVE) Save
Generate VRSAVE instructions when generating AltiVec code.

mvrsave=no
Target RejectNegative Alias(mvrsave) NegativeAlias Warn(%<-mvrsave=no%> is deprecated; use %<-mno-vrsave%> instead)
Deprecated option.  Use -mno-vrsave instead.

mvrsave=yes
Target RejectNegative Alias(mvrsave) Warn(%<-mvrsave=yes%> is deprecated; use %<-mvrsave%> instead)
Deprecated option.  Use -mvrsave instead.

mblock-move-inline-limit=
Target Report Var(rs6000_block_move_inline_limit) Init(0) RejectNegative Joined UInteger Save
Max number of bytes to move inline.

mblock-compare-inline-limit=
Target Report Var(rs6000_block_compare_inline_limit) Init(31) RejectNegative Joined UInteger Save
Max number of bytes to compare without loops.

mblock-compare-inline-loop-limit=
Target Report Var(rs6000_block_compare_inline_loop_limit) Init(-1) RejectNegative Joined UInteger Save
Max number of bytes to compare with loops.

mstring-compare-inline-limit=
Target Report Var(rs6000_string_compare_inline_limit) Init(64) RejectNegative Joined UInteger Save
Max number of bytes to compare.

misel
Target Report Mask(ISEL) Var(rs6000_isa_flags)
Generate isel instructions.

misel=no
Target RejectNegative Alias(misel) NegativeAlias Warn(%<-misel=no%> is deprecated; use %<-mno-isel%> instead)
Deprecated option.  Use -mno-isel instead.

misel=yes
Target RejectNegative Alias(misel) Warn(%<-misel=yes%> is deprecated; use %<-misel%> instead)
Deprecated option.  Use -misel instead.

mdebug=
Target RejectNegative Joined
-mdebug=	Enable debug output.

mabi=altivec
Target RejectNegative Var(rs6000_altivec_abi) Save
Use the AltiVec ABI extensions.

mabi=no-altivec
Target RejectNegative Var(rs6000_altivec_abi, 0)
Do not use the AltiVec ABI extensions.

mabi=elfv1
Target RejectNegative Var(rs6000_elf_abi, 1) Save
Use the ELFv1 ABI.

mabi=elfv2
Target RejectNegative Var(rs6000_elf_abi, 2)
Use the ELFv2 ABI.

; These are here for testing during development only, do not document
; in the manual please.

; If we want Darwin's struct-by-value-in-regs ABI.
mabi=d64
Target RejectNegative Undocumented Warn(using darwin64 ABI) Var(rs6000_darwin64_abi) Save

mabi=d32
Target RejectNegative Undocumented Warn(using old darwin ABI) Var(rs6000_darwin64_abi, 0)

mabi=ieeelongdouble
Target RejectNegative Var(rs6000_ieeequad) Save

mabi=ibmlongdouble
Target RejectNegative Var(rs6000_ieeequad, 0)

mcpu=
Target RejectNegative Joined Var(rs6000_cpu_index) Init(-1) Enum(rs6000_cpu_opt_value) Save
-mcpu=	Use features of and schedule code for given CPU.

mtune=
Target RejectNegative Joined Var(rs6000_tune_index) Init(-1) Enum(rs6000_cpu_opt_value) Save
-mtune=	Schedule code for given CPU.

mtraceback=
Target RejectNegative Joined Enum(rs6000_traceback_type) Var(rs6000_traceback)
-mtraceback=[full,part,no]	Select type of traceback table.

Enum
Name(rs6000_traceback_type) Type(enum rs6000_traceback_type)

EnumValue
Enum(rs6000_traceback_type) String(full) Value(traceback_full)

EnumValue
Enum(rs6000_traceback_type) String(part) Value(traceback_part)

EnumValue
Enum(rs6000_traceback_type) String(no) Value(traceback_none)

mlongcall
Target Report Var(rs6000_default_long_calls) Save
Avoid all range limits on call instructions.

; This option existed in the past, but now is always on.
mgen-cell-microcode
Target RejectNegative Undocumented Ignore

mwarn-altivec-long
Target Var(rs6000_warn_altivec_long) Init(1) Save
Warn about deprecated 'vector long ...' AltiVec type usage.

mlong-double-
Target RejectNegative Joined UInteger Var(rs6000_long_double_type_size) Save
-mlong-double-[64,128]	Specify size of long double.

; This option existed in the past, but now is always on.
mlra
Target RejectNegative Undocumented Ignore

msched-costly-dep=
Target RejectNegative Joined Var(rs6000_sched_costly_dep_str)
Determine which dependences between insns are considered costly.

minsert-sched-nops=
Target RejectNegative Joined Var(rs6000_sched_insert_nops_str)
Specify which post scheduling nop insertion scheme to apply.

malign-
Target RejectNegative Joined Enum(rs6000_alignment_flags) Var(rs6000_alignment_flags)
Specify alignment of structure fields default/natural.

Enum
Name(rs6000_alignment_flags) Type(unsigned char)
Valid arguments to -malign-:

EnumValue
Enum(rs6000_alignment_flags) String(power) Value(MASK_ALIGN_POWER)

EnumValue
Enum(rs6000_alignment_flags) String(natural) Value(MASK_ALIGN_NATURAL)

mprioritize-restricted-insns=
Target RejectNegative Joined UInteger Var(rs6000_sched_restricted_insns_priority) Save
Specify scheduling priority for dispatch slot restricted insns.

mpointers-to-nested-functions
Target Report Var(TARGET_POINTERS_TO_NESTED_FUNCTIONS) Init(1) Save
Use r11 to hold the static link in calls to functions via pointers.

msave-toc-indirect
Target Report Mask(SAVE_TOC_INDIRECT) Var(rs6000_isa_flags)
Save the TOC in the prologue for indirect calls rather than inline.

; This option existed in the past, but now is always the same as -mvsx.
mvsx-timode
Target RejectNegative Undocumented Ignore

mpower8-fusion
Target Report Mask(P8_FUSION) Var(rs6000_isa_flags)
Fuse certain integer operations together for better performance on power8.

mpower8-fusion-sign
Target Undocumented Mask(P8_FUSION_SIGN) Var(rs6000_isa_flags)
Allow sign extension in fusion operations.

mpower8-vector
Target Report Mask(P8_VECTOR) Var(rs6000_isa_flags)
Use vector and scalar instructions added in ISA 2.07.

mcrypto
Target Report Mask(CRYPTO) Var(rs6000_isa_flags)
Use ISA 2.07 Category:Vector.AES and Category:Vector.SHA2 instructions.

; We can't use Ignore flag because DIRECT_MOVE mask is still used.
mdirect-move
Target Undocumented Mask(DIRECT_MOVE) Var(rs6000_isa_flags) Warn(%qs is deprecated)

mhtm
Target Report Mask(HTM) Var(rs6000_isa_flags)
Use ISA 2.07 transactional memory (HTM) instructions.

mquad-memory
Target Report Mask(QUAD_MEMORY) Var(rs6000_isa_flags)
Generate the quad word memory instructions (lq/stq).

mquad-memory-atomic
Target Report Mask(QUAD_MEMORY_ATOMIC) Var(rs6000_isa_flags)
Generate the quad word memory atomic instructions (lqarx/stqcx).

mcompat-align-parm
Target Report Var(rs6000_compat_align_parm) Init(0) Save
Generate aggregate parameter passing code with at most 64-bit alignment.

moptimize-swaps
Target Undocumented Var(rs6000_optimize_swaps) Init(1) Save
Analyze and remove doubleword swaps from VSX computations.

mpower9-fusion
Target Undocumented Report Mask(P9_FUSION) Var(rs6000_isa_flags)
Fuse certain operations together for better performance on power9.

mpower9-misc
Target Undocumented Report Mask(P9_MISC) Var(rs6000_isa_flags)
Use certain scalar instructions added in ISA 3.0.

mpower9-vector
Target Undocumented Report Mask(P9_VECTOR) Var(rs6000_isa_flags)
Use vector instructions added in ISA 3.0.

mpower9-minmax
Target Undocumented Mask(P9_MINMAX) Var(rs6000_isa_flags)
Use the new min/max instructions defined in ISA 3.0.

mtoc-fusion
Target Undocumented Mask(TOC_FUSION) Var(rs6000_isa_flags)
Fuse medium/large code model toc references with the memory instruction.

mmodulo
Target Undocumented Report Mask(MODULO) Var(rs6000_isa_flags)
Generate the integer modulo instructions.

mfloat128
Target Report Mask(FLOAT128_KEYWORD) Var(rs6000_isa_flags)
Enable IEEE 128-bit floating point via the __float128 keyword.

mfloat128-hardware
Target Report Mask(FLOAT128_HW) Var(rs6000_isa_flags)
Enable using IEEE 128-bit floating point instructions.

mfloat128-convert
Target Undocumented Mask(FLOAT128_CVT) Var(rs6000_isa_flags)
Enable default conversions between __float128 & long double.

mstack-protector-guard=
Target RejectNegative Joined Enum(stack_protector_guard) Var(rs6000_stack_protector_guard) Init(SSP_TLS)
Use given stack-protector guard.

Enum
Name(stack_protector_guard) Type(enum stack_protector_guard)
Valid arguments to -mstack-protector-guard=:

EnumValue
Enum(stack_protector_guard) String(tls) Value(SSP_TLS)

EnumValue
Enum(stack_protector_guard) String(global) Value(SSP_GLOBAL)

mstack-protector-guard-reg=
Target RejectNegative Joined Var(rs6000_stack_protector_guard_reg_str)
Use the given base register for addressing the stack-protector guard.

TargetVariable
int rs6000_stack_protector_guard_reg = 0

mstack-protector-guard-offset=
Target RejectNegative Joined Integer Var(rs6000_stack_protector_guard_offset_str)
Use the given offset for addressing the stack-protector guard.

TargetVariable
long rs6000_stack_protector_guard_offset = 0

;; -mno-speculate-indirect-jumps adds deliberate misprediction to indirect
;; branches via the CTR.
mspeculate-indirect-jumps
Target Undocumented Var(rs6000_speculate_indirect_jumps) Init(1) Save

moptimize-addresses
Target Undocumented Init(0) Var(optimize_addr_num, 4) Save
Enable optimizing addresses for systems with fusion.

moptimize-addresses=
Target Undocumented RejectNegative Joined UInteger Var(optimize_addr_num)
Specify how many separate TOC pointers should be saved.

moptimize-addresses-fusion
Target Undocumented Init(0) Var(optimize_addr_fusion_num, 4) Save
Number of GPR loads to allow for power8 fusion without saving TOCs.

moptimize-addresses-fusion=
Target Undocumented RejectNegative Joined UInteger Var(optimize_addr_fusion_num)
Specify how many separate GPR loads to allow without saving TOCs.