On 11/03/2017 02:38 AM, Uros Bizjak wrote:
* config/i386/i386.c (ix86_emit_restore_reg_using_pop): Prototype. (ix86_adjust_stack_and_probe_stack_clash): Use a push/pop sequence to probe at the start of a noreturn function.* gcc.target/i386/stack-check-12.c: New test- emit_stack_probe (plus_constant (Pmode, stack_pointer_rtx, - -GET_MODE_SIZE (word_mode))); + rtx_insn *insn = emit_insn (gen_push (gen_rtx_REG (word_mode, 0))); Please use AX_REG instead of 0. + RTX_FRAME_RELATED_P (insn) = 1; + ix86_emit_restore_reg_using_pop (gen_rtx_REG (word_mode, 0)); Also here. emit_insn (gen_blockage ()); BTW: Could we use an unused register here, if available? %eax is used to pass first argument in regparm functions on 32bit targets.
Any register is sufficient. We just want to touch the top of the stack. Jeff
