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| author | Jim Wilson <wilson@gcc.gnu.org> | 1995-12-09 15:11:50 -0800 |
|---|---|---|
| committer | Jim Wilson <wilson@gcc.gnu.org> | 1995-12-09 15:11:50 -0800 |
| commit | caca3c8a0325fb2b5fc674777ad658bc5058b6c0 (patch) | |
| tree | 63fdc5001622d681be5da5baf9ed0536ee473aa5 /gcc | |
| parent | 06ada9d1c1b11112e676aff4c41a683c67028fbc (diff) | |
| download | gcc-caca3c8a0325fb2b5fc674777ad658bc5058b6c0.zip gcc-caca3c8a0325fb2b5fc674777ad658bc5058b6c0.tar.gz gcc-caca3c8a0325fb2b5fc674777ad658bc5058b6c0.tar.bz2 | |
(subsi3): Rename to subsi3_internal.
(subsi3): Rename to subsi3_internal. Add new define_expand
to handle subtracting a register from a constant.
From-SVN: r10693
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/config/sh/sh.md | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/gcc/config/sh/sh.md b/gcc/config/sh/sh.md index 3b767fb..898b508 100644 --- a/gcc/config/sh/sh.md +++ b/gcc/config/sh/sh.md @@ -321,13 +321,33 @@ "clrt\;subc %R2,%R0\;subc %S2,%S0" [(set_attr "length" "6")]) -(define_insn "subsi3" +(define_insn "*subsi3_internal" [(set (match_operand:SI 0 "arith_reg_operand" "=r") (minus:SI (match_operand:SI 1 "arith_reg_operand" "0") (match_operand:SI 2 "arith_reg_operand" "r")))] "" "sub %2,%0" [(set_attr "type" "arith")]) + +;; Convert `constant - reg' to `neg rX; add rX, #const' since this +;; will sometimes save one instruction. Otherwise we might get +;; `mov #const, rY; sub rY,rX; mov rX, rY' if the source and dest regs +;; are the same. + +(define_expand "subsi3" + [(set (match_operand:SI 0 "arith_reg_operand" "") + (minus:SI (match_operand:SI 1 "arith_operand" "") + (match_operand:SI 2 "arith_reg_operand" "")))] + "" + " +{ + if (GET_CODE (operands[1]) == CONST_INT) + { + emit_insn (gen_negsi2 (operands[0], operands[2])); + emit_insn (gen_addsi3 (operands[0], operands[0], operands[1])); + DONE; + } +}") ;; ------------------------------------------------------------------------- ;; Division instructions |