3.18.11 C-SKY Options

GCC supports these options when compiling for C-SKY V2 processors.

-march= arch
Specify the C-SKY target architecture. Valid values for arch are: ‘ ck801 ’, ‘ ck802 ’, ‘ ck803 ’, ‘ ck807 ’, and ‘ ck810 ’. The default is ‘ ck810 ’.
-mcpu= cpu
Specify the C-SKY target processor. Valid values for cpu are: ‘ ck801 ’, ‘ ck801t ’, ‘ ck802 ’, ‘ ck802t ’, ‘ ck802j ’, ‘ ck803 ’, ‘ ck803h ’, ‘ ck803t ’, ‘ ck803ht ’, ‘ ck803f ’, ‘ ck803fh ’, ‘ ck803e ’, ‘ ck803eh ’, ‘ ck803et ’, ‘ ck803eht ’, ‘ ck803ef ’, ‘ ck803efh ’, ‘ ck803ft ’, ‘ ck803eft ’, ‘ ck803efht ’, ‘ ck803r1 ’, ‘ ck803hr1 ’, ‘ ck803tr1 ’, ‘ ck803htr1 ’, ‘ ck803fr1 ’, ‘ ck803fhr1 ’, ‘ ck803er1 ’, ‘ ck803ehr1 ’, ‘ ck803etr1 ’, ‘ ck803ehtr1 ’, ‘ ck803efr1 ’, ‘ ck803efhr1 ’, ‘ ck803ftr1 ’, ‘ ck803eftr1 ’, ‘ ck803efhtr1 ’, ‘ ck803s ’, ‘ ck803st ’, ‘ ck803se ’, ‘ ck803sf ’, ‘ ck803sef ’, ‘ ck803seft ’, ‘ ck807e ’, ‘ ck807ef ’, ‘ ck807 ’, ‘ ck807f ’, ‘ ck810e ’, ‘ ck810et ’, ‘ ck810ef ’, ‘ ck810eft ’, ‘ ck810 ’, ‘ ck810v ’, ‘ ck810f ’, ‘ ck810t ’, ‘ ck810fv ’, ‘ ck810tv ’, ‘ ck810ft ’, and ‘ ck810ftv ’.
-mbig-endian
-EB
-mlittle-endian
-EL
Select big- or little-endian code. The default is little-endian.
-mhard-float
-msoft-float
Select hardware or software floating-point implementations. The default is soft float.
-mdouble-float
-mno-double-float
When -mhard-float is in effect, enable generation of double-precision float instructions. This is the default except when compiling for CK803.
-mfdivdu
-mno-fdivdu
When -mhard-float is in effect, enable generation of frecipd , fsqrtd , and fdivd instructions. This is the default except when compiling for CK803.
-mfpu= fpu
Select the floating-point processor. This option can only be used with -mhard-float . Values for fpu are ‘ fpv2_sf ’ (equivalent to ‘ -mno-double-float -mno-fdivdu ’), ‘ fpv2 ’ (‘ -mdouble-float -mno-divdu ’), and ‘ fpv2_divd ’ (‘ -mdouble-float -mdivdu ’).
-melrw
-mno-elrw
Enable the extended lrw instruction. This option defaults to on for CK801 and off otherwise.
-mistack
-mno-istack
Enable interrupt stack instructions; the default is off.

The -mistack option is required to handle the interrupt and isr function attributes (see C-SKY Function Attributes ).

-mmp
Enable multiprocessor instructions; the default is off.
-mcp
Enable coprocessor instructions; the default is off.
-mcache
Enable coprocessor instructions; the default is off.
-msecurity
Enable C-SKY security instructions; the default is off.
-mtrust
Enable C-SKY trust instructions; the default is off.
-mdsp
-medsp
-mvdsp
Enable C-SKY DSP, Enhanced DSP, or Vector DSP instructions, respectively. All of these options default to off.
-mdiv
-mno-div
Generate divide instructions. Default is off.
-msmart
-mno-smart
Generate code for Smart Mode, using only registers numbered 0-7 to allow use of 16-bit instructions. This option is ignored for CK801 where this is the required behavior, and it defaults to on for CK802. For other targets, the default is off.
-mhigh-registers
-mno-high-registers
Generate code using the high registers numbered 16-31. This option is not supported on CK801, CK802, or CK803, and is enabled by default for other processors.
-manchor
-mno-anchor
Generate code using global anchor symbol addresses.
-mpushpop
-mno-pushpop
Generate code using push and pop instructions. This option defaults to on.
-mmultiple-stld
-mstm
-mno-multiple-stld
-mno-stm
Generate code using stm and ldm instructions. This option isn't supported on CK801 but is enabled by default on other processors.
-mconstpool
-mno-constpool
Create constant pools in the compiler instead of deferring it to the assembler. This option is the default and required for correct code generation on CK801 and CK802, and is optional on other processors.
-mstack-size
-mno-stack-size
Emit .stack_size directives for each function in the assembly output. This option defaults to off.
-mccrt
-mno-ccrt
Generate code for the C-SKY compiler runtime instead of libgcc. This option defaults to off.
-mbranch-cost= n
Set the branch costs to roughly n instructions. The default is 1.
-msched-prolog
-mno-sched-prolog
Permit scheduling of function prologue and epilogue sequences. Using this option can result in code that is not compliant with the C-SKY V2 ABI prologue requirements and that cannot be debugged or backtraced. It is disabled by default.