diff options
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/config/rs6000/predicates.md | 4 | ||||
| -rw-r--r-- | gcc/config/rs6000/rs6000.md | 55 |
3 files changed, 43 insertions, 22 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index e88c8eb509e..4c1dd351489 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2005-08-23 Paolo Bonzini <bonzini@gnu.org> + + * config/rs6000/predicates.md (equality_operator): New. + * config/rs6000/rs6000.md: Rewrite as a peephole2 the split for + comparison with a large constant. + 2005-08-23 Mark Mitchell <mark@codesourcery.com> * hwint.h (HOST_WIDE_INT_PRINT): Use HOST_LONG_LONG_FORMAT. diff --git a/gcc/config/rs6000/predicates.md b/gcc/config/rs6000/predicates.md index 122ec45e856..3b5ef34a41b 100644 --- a/gcc/config/rs6000/predicates.md +++ b/gcc/config/rs6000/predicates.md @@ -710,6 +710,10 @@ (define_predicate "boolean_or_operator" (match_code "ior,xor")) +;; Return true if operand is an equality operator. +(define_special_predicate "equality_operator" + (match_code "eq,ne")) + ;; Return true if operand is MIN or MAX operator. (define_predicate "min_max_operator" (match_code "smin,smax,umin,umax")) diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md index 84db59fd14a..d1f810919ba 100644 --- a/gcc/config/rs6000/rs6000.md +++ b/gcc/config/rs6000/rs6000.md @@ -10729,32 +10729,43 @@ [(set_attr "type" "cmp")]) ;; If we are comparing a register for equality with a large constant, -;; we can do this with an XOR followed by a compare. But we need a scratch -;; register for the result of the XOR. +;; we can do this with an XOR followed by a compare. But this is profitable +;; only if the large constant is only used for the comparison (and in this +;; case we already have a register to reuse as scratch). -(define_split - [(set (match_operand:CC 0 "cc_reg_operand" "") - (compare:CC (match_operand:SI 1 "gpc_reg_operand" "") - (match_operand:SI 2 "non_short_cint_operand" ""))) - (clobber (match_operand:SI 3 "gpc_reg_operand" ""))] - "find_single_use (operands[0], insn, 0) - && (GET_CODE (*find_single_use (operands[0], insn, 0)) == EQ - || GET_CODE (*find_single_use (operands[0], insn, 0)) == NE)" - [(set (match_dup 3) (xor:SI (match_dup 1) (match_dup 4))) - (set (match_dup 0) (compare:CC (match_dup 3) (match_dup 5)))] - " -{ - /* Get the constant we are comparing against, C, and see what it looks like - sign-extended to 16 bits. Then see what constant could be XOR'ed - with C to get the sign-extended value. */ - - HOST_WIDE_INT c = INTVAL (operands[2]); +(define_peephole2 + [(set (match_operand:GPR 0 "register_operand") + (match_operand:GPR 1 "logical_operand" "")) + (set (match_dup 0) (match_operator:GPR 3 "boolean_or_operator" + [(match_dup 0) + (match_operand:GPR 2 "logical_operand" "")])) + (set (match_operand:CC 4 "cc_reg_operand" "") + (compare:CC (match_operand:GPR 5 "gpc_reg_operand" "") + (match_dup 0))) + (set (pc) + (if_then_else (match_operator 6 "equality_operator" + [(match_dup 4) (const_int 0)]) + (match_operand 7 "" "") + (match_operand 8 "" "")))] + "peep2_reg_dead_p (3, operands[0])" + [(set (match_dup 0) (xor:GPR (match_dup 5) (match_dup 9))) + (set (match_dup 4) (compare:CC (match_dup 0) (match_dup 10))) + (set (pc) (if_then_else (match_dup 6) (match_dup 7) (match_dup 8)))] + +{ + /* Get the constant we are comparing against, and see what it looks like + when sign-extended from 16 to 32 bits. Then see what constant we could + XOR with SEXTC to get the sign-extended value. */ + rtx cnst = simplify_const_binary_operation (GET_CODE (operands[3]), + GET_MODE (operands[3]), + operands[1], operands[2]); + HOST_WIDE_INT c = INTVAL (cnst); HOST_WIDE_INT sextc = ((c & 0xffff) ^ 0x8000) - 0x8000; HOST_WIDE_INT xorv = c ^ sextc; - operands[4] = GEN_INT (xorv); - operands[5] = GEN_INT (sextc); -}") + operands[9] = GEN_INT (xorv); + operands[10] = GEN_INT (sextc); +}) (define_insn "*cmpsi_internal2" [(set (match_operand:CCUNS 0 "cc_reg_operand" "=y") |