For APX, the inline asm behavior was not mentioned in any document
before. Add description for it.
gcc/ChangeLog:
* config/i386/i386.opt: Adjust document.
* doc/invoke.texi: Add description for
-mapx-inline-asm-use-gpr32.
mapx-inline-asm-use-gpr32
Target Var(ix86_apx_inline_asm_use_gpr32) Init(0)
-Enable GPR32 in inline asm when APX_EGPR enabled, do not
-hook reg or mem constraint in inline asm to GPR16.
+Enable GPR32 in inline asm when APX_F enabled.
mevex512
Target Mask(ISA2_EVEX512) Var(ix86_isa_flags2) Save
to allow them to be replaced with @samp{lfence; call *%r8-r15} or
@samp{lfence; jmp *%r8-r15} at run-time.
+@opindex mapx-inline-asm-use-gpr32
+@item -mapx-inline-asm-use-gpr32
+For inline asm support with APX, by default the EGPR feature was
+disabled to prevent potential illegal instruction with EGPR occurs.
+To invoke egpr usage in inline asm, use new compiler option
+-mapx-inline-asm-use-gpr32 and user should ensure the instruction
+supports EGPR.
+
@end table
These @samp{-m} switches are supported in addition to the above