Hello, This improves some cases where the T bit is stored as all ones or all zeros to a GP reg. Tested on rev 189916 with make -k check RUNTESTFLAGS="--target_board=sh-sim \{-m2/-ml,-m2/-mb,-m2a/-mb,-m2a-single/-mb,-m4/-ml,-m4/-mb, -m4-single/-ml,-m4-single/-mb,-m4a-single/-ml,-m4a-single/-mb}"
and no new failures. OK? Cheers, Oleg ChangeLog: PR target/51244 * config/sh/sh.md (mov_neg_si_t): Move to Scc instructions section. Use t_reg_operand predicate. Add split for negated case. (ashrsi2_31): Pass get_t_reg_rtx to gen_mov_neg_si_t. * config/sh/sh.c (expand_ashiftrt): Likewise. testsuite/ChangeLog: PR target/51244 * gcc.target/sh/pr51244-4.c: New.
Index: gcc/config/sh/sh.c =================================================================== --- gcc/config/sh/sh.c (revision 189917) +++ gcc/config/sh/sh.c (working copy) @@ -3481,7 +3481,7 @@ { emit_insn (gen_cmpgtsi_t (force_reg (SImode, CONST0_RTX (SImode)), operands[1])); - emit_insn (gen_mov_neg_si_t (operands[0])); + emit_insn (gen_mov_neg_si_t (operands[0], get_t_reg_rtx ())); return true; } emit_insn (gen_ashrsi2_31 (operands[0], operands[1])); Index: gcc/config/sh/sh.md =================================================================== --- gcc/config/sh/sh.md (revision 189916) +++ gcc/config/sh/sh.md (working copy) @@ -1584,15 +1584,6 @@ "subc %2,%0" [(set_attr "type" "arith")]) -;; life_analysis thinks rn is live before subc rn,rn, so make a special -;; pattern for this case. This helps multimedia applications that compute -;; the sum of absolute differences. -(define_insn "mov_neg_si_t" - [(set (match_operand:SI 0 "arith_reg_dest" "=r") (neg:SI (reg:SI T_REG)))] - "TARGET_SH1" - "subc %0,%0" - [(set_attr "type" "arith")]) - (define_insn "*subsi3_internal" [(set (match_operand:SI 0 "arith_reg_dest" "=r") (minus:SI (match_operand:SI 1 "arith_reg_operand" "0") @@ -3797,7 +3788,7 @@ [(const_int 0)] { emit_insn (gen_ashlsi_c (operands[0], operands[1])); - emit_insn (gen_mov_neg_si_t (copy_rtx (operands[0]))); + emit_insn (gen_mov_neg_si_t (operands[0], get_t_reg_rtx ())); DONE; }) @@ -9704,6 +9695,25 @@ "" [(const_int 0)]) +;; Store T bit as all zeros or ones in a reg. +(define_insn "mov_neg_si_t" + [(set (match_operand:SI 0 "arith_reg_dest" "=r") + (neg:SI (match_operand 1 "t_reg_operand" "")))] + "TARGET_SH1" + "subc %0,%0" + [(set_attr "type" "arith")]) + +;; Store negated T bit as all zeros or ones in a reg. +;; Use the following sequence: +;; subc Rn,Rn ! Rn = Rn - Rn - T; T = T +;; not Rn,Rn ! Rn = 0 - Rn +(define_split + [(set (match_operand:SI 0 "arith_reg_dest" "") + (neg:SI (match_operand 1 "negt_reg_operand" "")))] + "TARGET_SH1" + [(set (match_dup 0) (neg:SI (reg:SI T_REG))) + (set (match_dup 0) (not:SI (match_dup 0)))]) + ;; The *movtt pattern eliminates redundant T bit to T bit moves / tests. (define_insn_and_split "*movtt" [(set (reg:SI T_REG) Index: gcc/testsuite/gcc.target/sh/pr51244-4.c =================================================================== --- gcc/testsuite/gcc.target/sh/pr51244-4.c (revision 0) +++ gcc/testsuite/gcc.target/sh/pr51244-4.c (revision 0) @@ -0,0 +1,19 @@ +/* Check that storing the (negated) T bit as all ones or zeros in a reg + uses the subc instruction. On SH2A a sequence with the movrt instruction + is also OK instead of subc. */ +/* { dg-do compile { target "sh*-*-*" } } */ +/* { dg-options "-O1 -mbranch-cost=2" } */ +/* { dg-skip-if "" { "sh*-*-*" } { "-m5*"} { "" } } */ +/* { dg-final { scan-assembler-not "movt|tst|negc" } } */ +/* { dg-final { scan-assembler "subc|movrt|neg|not" } } */ + +int test_00 (int x, int y) +{ + return x != y ? -1 : 0; +} + +int test_01 (int x, int y) +{ + return x == y ? -1 : 0; +} +