diff options
Diffstat (limited to 'gcc/config')
| -rw-r--r-- | gcc/config/i386/i386.md | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md index d15170e..c8fbf60 100644 --- a/gcc/config/i386/i386.md +++ b/gcc/config/i386/i386.md @@ -3180,6 +3180,38 @@ (const_int 8)) (subreg:SWI248 (match_dup 1) 0))]) +;; Eliminate redundant insv, e.g. xorl %eax,%eax; movb $0, %ah +(define_peephole2 + [(parallel [(set (match_operand:SWI48 0 "general_reg_operand") + (const_int 0)) + (clobber (reg:CC FLAGS_REG))]) + (set (zero_extract:SWI248 (match_operand:SWI248 1 "general_reg_operand") + (const_int 8) + (const_int 8)) + (const_int 0))] + "REGNO (operands[0]) == REGNO (operands[1])" + [(parallel [(set (match_operand:SWI48 0 "general_reg_operand") + (const_int 0)) + (clobber (reg:CC FLAGS_REG))])]) + +;; Combine movl followed by movb. +(define_peephole2 + [(set (match_operand:SWI48 0 "general_reg_operand") + (match_operand:SWI48 1 "const_int_operand")) + (set (zero_extract:SWI248 (match_operand:SWI248 2 "general_reg_operand") + (const_int 8) + (const_int 8)) + (match_operand:SWI248 3 "const_int_operand"))] + "REGNO (operands[0]) == REGNO (operands[2])" + [(set (match_operand:SWI48 0 "general_reg_operand") + (match_dup 4))] +{ + HOST_WIDE_INT tmp = INTVAL (operands[1]) & ~(HOST_WIDE_INT)0xff00; + tmp |= (INTVAL (operands[3]) & 0xff) << 8; + operands[4] = gen_int_mode (tmp, <SWI48:MODE>mode); +}) + + (define_code_iterator any_extract [sign_extract zero_extract]) (define_insn "*insvqi_2" @@ -4276,6 +4308,24 @@ [(set_attr "isa" "*,avx512dq,avx512dq") (set_attr "type" "imovx,mskmov,mskmov") (set_attr "mode" "SI,QI,QI")]) + +;; Transform xorl; mov[bw] (set strict_low_part) into movz[bw]l. +(define_peephole2 + [(parallel [(set (match_operand:SWI48 0 "general_reg_operand") + (const_int 0)) + (clobber (reg:CC FLAGS_REG))]) + (set (strict_low_part (match_operand:SWI12 1 "general_reg_operand")) + (match_operand:SWI12 2 "nonimmediate_operand"))] + "REGNO (operands[0]) == REGNO (operands[1])" + [(set (match_dup 0) (zero_extend:SWI48 (match_dup 2)))]) + +;; Likewise, but preserving FLAGS_REG. +(define_peephole2 + [(set (match_operand:SWI48 0 "general_reg_operand") (const_int 0)) + (set (strict_low_part (match_operand:SWI12 1 "general_reg_operand")) + (match_operand:SWI12 2 "nonimmediate_operand"))] + "REGNO (operands[0]) == REGNO (operands[1])" + [(set (match_dup 0) (zero_extend:SWI48 (match_dup 2)))]) ;; Sign extension instructions |