https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101743
Hongtao.liu <crazylht at gmail dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |crazylht at gmail dot com --- Comment #1 from Hongtao.liu <crazylht at gmail dot com> --- +;; Eliminate a reg-reg mov by inverting the condition of a cmov (#1). +;; mov r0,r1; dec r0; mov r2,r3; cmov r0,r2 -> dec r1; mov r0,r3; cmov r0, r1 +(define_peephole2 + [(set (match_operand:SWI248 0 "register_operand") + (match_operand:SWI248 1 "register_operand")) + (parallel [(set (reg FLAGS_REG) (match_operand 5)) + (set (match_dup 0) (match_operand:SWI248 6))]) + (set (match_operand:SWI248 2 "register_operand") + (match_operand:SWI248 3)) + (set (match_dup 0) + (if_then_else:SWI248 (match_operator 4 "ix86_comparison_operator" + [(reg FLAGS_REG) (const_int 0)]) + (match_dup 0) + (match_dup 2)))] + "TARGET_CMOVE + && REGNO (operands[2]) != REGNO (operands[0]) + && REGNO (operands[2]) != REGNO (operands[1]) + && peep2_reg_dead_p (1, operands[1]) + && peep2_reg_dead_p (4, operands[2]) + && !reg_overlap_mentioned_p (operands[0], operands[3])" + [(parallel [(set (match_dup 7) (match_dup 8)) + (set (match_dup 1) (match_dup 9))]) + (set (match_dup 0) (match_dup 3)) + (set (match_dup 0) (if_then_else:SWI248 (match_dup 4) + (match_dup 1) + (match_dup 0)))] +{ + operands[7] = SET_DEST (XVECEXP (PATTERN (peep2_next_insn (1)), 0, 0)); + operands[8] = replace_rtx (operands[5], operands[0], operands[1]); + operands[9] = replace_rtx (operands[6], operands[0], operands[1]); +}) + +;; Eliminate a reg-reg mov by inverting the condition of a cmov (#2). +;; mov r2,r3; mov r0,r1; dec r0; cmov r0,r2 -> dec r1; mov r0,r3; cmov r0, r1 I guess the below peephole should refine its predicate as general_reg_operand, since x86 support movement between gpr, sse, mask registers. r1 here is very likely sse_reg_operand which result in ICE. +(define_peephole2 + [(set (match_operand:SWI248 2 "register_operand") + (match_operand:SWI248 3)) + (set (match_operand:SWI248 0 "register_operand") + (match_operand:SWI248 1 "register_operand")) + (parallel [(set (reg FLAGS_REG) (match_operand 5)) + (set (match_dup 0) (match_operand:SWI248 6))]) + (set (match_dup 0) + (if_then_else:SWI248 (match_operator 4 "ix86_comparison_operator" + [(reg FLAGS_REG) (const_int 0)]) + (match_dup 0) + (match_dup 2)))] + "TARGET_CMOVE + && REGNO (operands[2]) != REGNO (operands[0]) + && REGNO (operands[2]) != REGNO (operands[1]) + && peep2_reg_dead_p (2, operands[1]) + && peep2_reg_dead_p (4, operands[2]) + && !reg_overlap_mentioned_p (operands[0], operands[3])" + [(parallel [(set (match_dup 7) (match_dup 8)) + (set (match_dup 1) (match_dup 9))]) + (set (match_dup 0) (match_dup 3)) + (set (match_dup 0) (if_then_else:SWI248 (match_dup 4) + (match_dup 1) + (match_dup 0)))] +{ + operands[7] = SET_DEST (XVECEXP (PATTERN (peep2_next_insn (2)), 0, 0)); + operands[8] = replace_rtx (operands[5], operands[0], operands[1]); + operands[9] = replace_rtx (operands[6], operands[0], operands[1]); +}) +