gcc/config/s390/s390.opt

   1 ; Options for the S/390 / zSeries port of the compiler.
   2
   3 ; Copyright (C) 2005-2025 Free Software Foundation, Inc.
   4 ;
   5 ; This file is part of GCC.
   6 ;
   7 ; GCC is free software; you can redistribute it and/or modify it under
   8 ; the terms of the GNU General Public License as published by the Free
   9 ; Software Foundation; either version 3, or (at your option) any later
  10 ; version.
  11 ;
  12 ; GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 ; WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 ; FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 ; for more details.
  16 ;
  17 ; You should have received a copy of the GNU General Public License
  18 ; along with GCC; see the file COPYING3.  If not see
  19 ; <http://www.gnu.org/licenses/>.
  20
  21 HeaderInclude
  22 config/s390/s390-opts.h
  23
  24 ;; Definitions to add to the cl_target_option and gcc_options structures
  25
  26 ;; whether -march was specified
  27 TargetVariable
  28 unsigned char s390_arch_specified
  29
  30 ;; Flags derived from s390_arch
  31 TargetVariable
  32 int s390_arch_flags
  33
  34 ;; whether -mtune was specified
  35 TargetVariable
  36 unsigned char s390_tune_specified
  37
  38 ;; Flags derived from s390_tune
  39 TargetVariable
  40 int s390_tune_flags
  41
  42 ;; Cpu cost table (this is actually a "const struct processor_cost *")
  43 Variable
  44 long s390_cost_pointer
  45
  46 m31
  47 Target RejectNegative Negative(m64) InverseMask(64BIT)
  48 31 bit ABI.
  49
  50 m64
  51 Target RejectNegative Negative(m31) Mask(64BIT)
  52 64 bit ABI.
  53
  54 march=
  55 Target RejectNegative Joined Enum(processor_type) Var(s390_arch) Init(PROCESSOR_max) Save
  56 Generate code for given CPU.
  57
  58 Enum
  59 Name(processor_type) Type(enum processor_type)
  60
  61 EnumValue
  62 Enum(processor_type) String(z900) Value(PROCESSOR_2064_Z900)
  63
  64 EnumValue
  65 Enum(processor_type) String(arch5) Value(PROCESSOR_2064_Z900)
  66
  67 EnumValue
  68 Enum(processor_type) String(z990) Value(PROCESSOR_2084_Z990)
  69
  70 EnumValue
  71 Enum(processor_type) String(arch6) Value(PROCESSOR_2084_Z990)
  72
  73 EnumValue
  74 Enum(processor_type) String(z9-109) Value(PROCESSOR_2094_Z9_109)
  75
  76 EnumValue
  77 Enum(processor_type) String(z9-ec) Value(PROCESSOR_2094_Z9_EC)
  78
  79 EnumValue
  80 Enum(processor_type) String(arch7) Value(PROCESSOR_2094_Z9_EC)
  81
  82 EnumValue
  83 Enum(processor_type) String(z10) Value(PROCESSOR_2097_Z10)
  84
  85 EnumValue
  86 Enum(processor_type) String(arch8) Value(PROCESSOR_2097_Z10)
  87
  88 EnumValue
  89 Enum(processor_type) String(z196) Value(PROCESSOR_2817_Z196)
  90
  91 EnumValue
  92 Enum(processor_type) String(arch9) Value(PROCESSOR_2817_Z196)
  93
  94 EnumValue
  95 Enum(processor_type) String(zEC12) Value(PROCESSOR_2827_ZEC12)
  96
  97 EnumValue
  98 Enum(processor_type) String(arch10) Value(PROCESSOR_2827_ZEC12)
  99
 100 EnumValue
 101 Enum(processor_type) String(z13) Value(PROCESSOR_2964_Z13)
 102
 103 EnumValue
 104 Enum(processor_type) String(arch11) Value(PROCESSOR_2964_Z13)
 105
 106 EnumValue
 107 Enum(processor_type) String(z14) Value(PROCESSOR_3906_Z14)
 108
 109 EnumValue
 110 Enum(processor_type) String(arch12) Value(PROCESSOR_3906_Z14)
 111
 112 EnumValue
 113 Enum(processor_type) String(z15) Value(PROCESSOR_8561_Z15)
 114
 115 EnumValue
 116 Enum(processor_type) String(arch13) Value(PROCESSOR_8561_Z15)
 117
 118 EnumValue
 119 Enum(processor_type) String(arch14) Value(PROCESSOR_3931_Z16)
 120
 121 EnumValue
 122 Enum(processor_type) String(z16) Value(PROCESSOR_3931_Z16)
 123
 124 EnumValue
 125 Enum(processor_type) String(arch15) Value(PROCESSOR_9175_Z17)
 126
 127 EnumValue
 128 Enum(processor_type) String(z17) Value(PROCESSOR_9175_Z17)
 129
 130 EnumValue
 131 Enum(processor_type) String(native) Value(PROCESSOR_NATIVE) DriverOnly
 132
 133 mbackchain
 134 Target Mask(BACKCHAIN) Save
 135 Maintain backchain pointer.
 136
 137 mdebug
 138 Target Mask(DEBUG_ARG) Save
 139 Additional debug prints.
 140
 141 mesa
 142 Target RejectNegative Negative(mzarch) InverseMask(ZARCH)
 143 ESA/390 architecture.
 144
 145 mhard-dfp
 146 Target Mask(HARD_DFP) Save
 147 Enable decimal floating point hardware support.
 148
 149 mhard-float
 150 Target RejectNegative Negative(msoft-float) InverseMask(SOFT_FLOAT, HARD_FLOAT) Save
 151 Enable hardware floating point.
 152
 153 mhotpatch=
 154 Target RejectNegative Joined Var(s390_deferred_options) Defer
 155 Takes two non-negative integer numbers separated by a comma.
 156 Prepend the function label with the number of two-byte Nop
 157 instructions indicated by the first.  Append Nop instructions
 158 covering the number of halfwords indicated by the second after the
 159 label.  Nop instructions of the largest possible size are used
 160 (six, four or two bytes), beginning with the largest possible
 161 size.  Using 0 for both values disables hotpatching.
 162
 163 mlong-double-128
 164 Target RejectNegative Negative(mlong-double-64) Mask(LONG_DOUBLE_128)
 165 Use 128-bit long double.
 166
 167 mlong-double-64
 168 Target RejectNegative Negative(mlong-double-128) InverseMask(LONG_DOUBLE_128)
 169 Use 64-bit long double.
 170
 171 mhtm
 172 Target Mask(OPT_HTM) Save
 173 Use hardware transactional execution instructions.
 174
 175 mvx
 176 Target Mask(OPT_VX) Save
 177 Use hardware vector facility instructions and enable the vector ABI.
 178
 179 mpacked-stack
 180 Target Mask(PACKED_STACK) Save
 181 Use packed stack layout.
 182
 183 msmall-exec
 184 Target Mask(SMALL_EXEC) Save
 185 Use bras for executable < 64k.
 186
 187 msoft-float
 188 Target RejectNegative Negative(mhard-float) Mask(SOFT_FLOAT) Save
 189 Disable hardware floating point.
 190
 191 mstack-guard=
 192 Target RejectNegative Negative(mno-stack-guard) Joined UInteger Var(s390_stack_guard) Save
 193 Set the max. number of bytes which has to be left to stack size before a trap instruction is triggered.
 194
 195 mno-stack-guard
 196 Target RejectNegative Alias(mstack-guard=,0) Negative(mstack-guard=)
 197 Switches off the -mstack-guard= option.
 198
 199 mstack-size=
 200 Target RejectNegative Joined UInteger Var(s390_stack_size) Save
 201 Emit extra code in the function prologue in order to trap if the stack size exceeds the given limit.
 202
 203 mno-stack-size
 204 Target RejectNegative Alias(mstack-size=,0) Negative(mstack-size=)
 205 Switches off the -mstack-size= option.
 206
 207 mtune=
 208 Target RejectNegative Joined Enum(processor_type) Var(s390_tune) Init(PROCESSOR_max) Save
 209 Schedule code for given CPU.
 210
 211 mmvcle
 212 Target Mask(MVCLE) Save
 213 Use the mvcle instruction for block moves.
 214
 215 mzvector
 216 Target Mask(ZVECTOR) Save
 217 Enable the z vector language extension providing the context-sensitive
 218 vector macro and enable the Altivec-style builtins in vecintrin.h.
 219
 220 mwarn-dynamicstack
 221 Target Var(s390_warn_dynamicstack_p) Save
 222 Warn if a function uses alloca or creates an array with dynamic size.
 223
 224 mwarn-framesize=
 225 Target RejectNegative Joined UInteger Var(s390_warn_framesize) Save
 226 Warn if a single function's framesize exceeds the given framesize.
 227
 228 mzarch
 229 Target RejectNegative Negative(mesa) Mask(ZARCH)
 230 z/Architecture.
 231
 232 mbranch-cost=
 233 Target Joined RejectNegative UInteger Var(s390_branch_cost) Init(1) Save
 234 Set the branch costs for conditional branch instructions.  Reasonable
 235 values are small, non-negative integers.  The default branch cost is
 236 1.
 237
 238 mpic-data-is-text-relative
 239 Target Var(s390_pic_data_is_text_relative) Init(TARGET_DEFAULT_PIC_DATA_IS_TEXT_RELATIVE)
 240 Assume data segments are relative to text segment.
 241
 242
 243 mindirect-branch=
 244 Target RejectNegative Joined Enum(indirect_branch) Var(s390_indirect_branch) Init(indirect_branch_keep)
 245 Wrap all indirect branches into execute in order to disable branch
 246 prediction.
 247
 248 mindirect-branch-jump=
 249 Target RejectNegative Joined Enum(indirect_branch) Var(s390_indirect_branch_jump) Init(indirect_branch_keep)
 250 Wrap indirect table jumps and computed gotos into execute in order to
 251 disable branch prediction.  Using thunk or thunk-extern with this
 252 option requires the thunks to be considered signal handlers to order to
 253 generate correct CFI.  For environments where unwinding (e.g. for
 254 exceptions) is required please use thunk-inline instead.
 255
 256 mindirect-branch-call=
 257 Target RejectNegative Joined Enum(indirect_branch) Var(s390_indirect_branch_call) Init(indirect_branch_keep)
 258 Wrap all indirect calls into execute in order to disable branch prediction.
 259
 260 mfunction-return=
 261 Target RejectNegative Joined Enum(indirect_branch) Var(s390_function_return) Init(indirect_branch_keep)
 262 Wrap all indirect return branches into execute in order to disable branch
 263 prediction.
 264
 265 mfunction-return-mem=
 266 Target RejectNegative Joined Enum(indirect_branch) Var(s390_function_return_mem) Init(indirect_branch_keep)
 267 Wrap indirect return branches into execute in order to disable branch
 268 prediction. This affects only branches where the return address is
 269 going to be restored from memory.
 270
 271 mfunction-return-reg=
 272 Target RejectNegative Joined Enum(indirect_branch) Var(s390_function_return_reg) Init(indirect_branch_keep)
 273 Wrap indirect return branches into execute in order to disable branch
 274 prediction. This affects only branches where the return address
 275 doesn't need to be restored from memory.
 276
 277 Enum
 278 Name(indirect_branch) Type(enum indirect_branch)
 279 Known indirect branch choices (for use with the -mindirect-branch=/-mfunction-return= options):
 280
 281 EnumValue
 282 Enum(indirect_branch) String(keep) Value(indirect_branch_keep)
 283
 284 EnumValue
 285 Enum(indirect_branch) String(thunk) Value(indirect_branch_thunk)
 286
 287 EnumValue
 288 Enum(indirect_branch) String(thunk-inline) Value(indirect_branch_thunk_inline)
 289
 290 EnumValue
 291 Enum(indirect_branch) String(thunk-extern) Value(indirect_branch_thunk_extern)
 292
 293 mindirect-branch-table
 294 Target Var(s390_indirect_branch_table) Init(TARGET_DEFAULT_INDIRECT_BRANCH_TABLE)
 295 Generate sections .s390_indirect_jump, .s390_indirect_call,
 296 .s390_return_reg, and .s390_return_mem to contain the indirect branch
 297 locations which have been patched as part of using one of the
 298 -mindirect-branch* or -mfunction-return* options.  The sections
 299 consist of an array of 32 bit elements. Each entry holds the offset
 300 from the entry to the patched location.
 301
 302 mfentry
 303 Target Var(flag_fentry)
 304 Emit profiling counter call at function entry before prologue. The compiled
 305 code will require a 64-bit CPU and glibc 2.29 or newer to run.
 306
 307 mrecord-mcount
 308 Target Var(flag_record_mcount)
 309 Generate __mcount_loc section with all _mcount and __fentry__ calls.
 310
 311 mnop-mcount
 312 Target Var(flag_nop_mcount)
 313 Generate mcount/__fentry__ calls as nops. To activate they need to be
 314 patched in.
 315
 316 mvx-long-double-fma
 317 Target Undocumented Var(flag_vx_long_double_fma)
 318 Emit fused multiply-add instructions for long doubles in vector registers
 319 (wfmaxb, wfmsxb, wfnmaxb, wfnmsxb).  Reassociation pass does not handle
 320 fused multiply-adds, therefore code generated by the middle-end is prone to
 321 having long fused multiply-add chains.  This is not pipeline-friendly,
 322 and the default behavior is to emit separate multiplication and addition
 323 instructions for long doubles in vector registers, because measurements show
 324 that this improves performance.  This option allows overriding it for testing
 325 purposes.
 326
 327 munroll-only-small-loops
 328 Target Undocumented Var(unroll_only_small_loops) Init(0) Save
 329 ; Use conservative small loop unrolling.
 330
 331 mpreserve-args
 332 Target Var(s390_preserve_args_p) Init(0)
 333 Store all argument registers on the stack.
 334
 335 munaligned-symbols
 336 Target Var(s390_unaligned_symbols_p) Init(0)
 337 Assume external symbols, whose natural alignment would be 1, to be
 338 potentially unaligned.  By default all symbols without explicit
 339 alignment are assumed to reside on a 2 byte boundary as mandated by
 340 the IBM Z ABI.
 341