diff options
Diffstat (limited to 'gcc/cse.c')
| -rw-r--r-- | gcc/cse.c | 77 |
1 files changed, 31 insertions, 46 deletions
diff --git a/gcc/cse.c b/gcc/cse.c index e69bb634ebb..abe4be80f60 100644 --- a/gcc/cse.c +++ b/gcc/cse.c @@ -3910,15 +3910,15 @@ fold_rtx (x, insn) if (const_arg0 == 0 || const_arg1 == 0) { struct table_elt *p0, *p1; - rtx true = const_true_rtx, false = const0_rtx; + rtx true_rtx = const_true_rtx, false_rtx = const0_rtx; enum machine_mode mode_arg1; #ifdef FLOAT_STORE_FLAG_VALUE if (GET_MODE_CLASS (mode) == MODE_FLOAT) { - true = (CONST_DOUBLE_FROM_REAL_VALUE + true_rtx = (CONST_DOUBLE_FROM_REAL_VALUE (FLOAT_STORE_FLAG_VALUE (mode), mode)); - false = CONST0_RTX (mode); + false_rtx = CONST0_RTX (mode); } #endif @@ -3952,9 +3952,9 @@ fold_rtx (x, insn) || GET_CODE (folded_arg0) == CONST)) { if (code == EQ) - return false; + return false_rtx; else if (code == NE) - return true; + return true_rtx; } /* See if the two operands are the same. */ @@ -3978,12 +3978,12 @@ fold_rtx (x, insn) return ((code == EQ || code == LE || code == GE || code == LEU || code == GEU || code == UNEQ || code == UNLE || code == UNGE || code == ORDERED) - ? true : false); + ? true_rtx : false_rtx); /* Take care for the FP compares we can resolve. */ if (code == UNEQ || code == UNLE || code == UNGE) - return true; + return true_rtx; if (code == LTGT || code == LT || code == GT) - return false; + return false_rtx; } /* If FOLDED_ARG0 is a register, see if the comparison we are @@ -4008,7 +4008,7 @@ fold_rtx (x, insn) || (GET_CODE (folded_arg1) == REG && (REG_QTY (REGNO (folded_arg1)) == ent->comparison_qty)))) return (comparison_dominates_p (ent->comparison_code, code) - ? true : false); + ? true_rtx : false_rtx); } } } @@ -4032,30 +4032,30 @@ fold_rtx (x, insn) int has_sign = (HOST_BITS_PER_WIDE_INT >= sign_bitnum && (INTVAL (inner_const) & ((HOST_WIDE_INT) 1 << sign_bitnum))); - rtx true = const_true_rtx, false = const0_rtx; + rtx true_rtx = const_true_rtx, false_rtx = const0_rtx; #ifdef FLOAT_STORE_FLAG_VALUE if (GET_MODE_CLASS (mode) == MODE_FLOAT) { - true = (CONST_DOUBLE_FROM_REAL_VALUE + true_rtx = (CONST_DOUBLE_FROM_REAL_VALUE (FLOAT_STORE_FLAG_VALUE (mode), mode)); - false = CONST0_RTX (mode); + false_rtx = CONST0_RTX (mode); } #endif switch (code) { case EQ: - return false; + return false_rtx; case NE: - return true; + return true_rtx; case LT: case LE: if (has_sign) - return true; + return true_rtx; break; case GT: case GE: if (has_sign) - return false; + return false_rtx; break; default: break; @@ -5513,31 +5513,17 @@ cse_insn (insn, libcall_insn) check for this separately here. We will delete such an insn below. - Tablejump insns contain a USE of the table, so simply replacing - the operand with the constant won't match. This is simply an - unconditional branch, however, and is therefore valid. Just - insert the substitution here and we will delete and re-emit - the insn later. */ - + For other cases such as a table jump or conditional jump + where we know the ultimate target, go ahead and replace the + operand. While that may not make a valid insn, we will + reemit the jump below (and also insert any necessary + barriers). */ if (n_sets == 1 && dest == pc_rtx && (trial == pc_rtx || (GET_CODE (trial) == LABEL_REF && ! condjump_p (insn)))) { - if (trial == pc_rtx) - { - SET_SRC (sets[i].rtl) = trial; - cse_jumps_altered = 1; - break; - } - - PATTERN (insn) = gen_jump (XEXP (trial, 0)); - INSN_CODE (insn) = -1; - - if (NEXT_INSN (insn) != 0 - && GET_CODE (NEXT_INSN (insn)) != BARRIER) - emit_barrier_after (insn); - + SET_SRC (sets[i].rtl) = trial; cse_jumps_altered = 1; break; } @@ -5799,13 +5785,17 @@ cse_insn (insn, libcall_insn) } /* If this SET is now setting PC to a label, we know it used to - be a conditional or computed branch. So we see if we can follow - it. If it was a computed branch, delete it and re-emit. */ + be a conditional or computed branch. */ else if (dest == pc_rtx && GET_CODE (src) == LABEL_REF) { - /* If this is not in the format for a simple branch and - we are the only SET in it, re-emit it. */ - if (! simplejump_p (insn) && n_sets == 1) + /* We reemit the jump in as many cases as possible just in + case the form of an unconditional jump is significantly + different than a computed jump or conditional jump. + + If this insn has multiple sets, then reemitting the + jump is nontrivial. So instead we just force rerecognition + and hope for the best. */ + if (n_sets == 1) { rtx new = emit_jump_insn_before (gen_jump (XEXP (src, 0)), insn); JUMP_LABEL (new) = XEXP (src, 0); @@ -5813,11 +5803,6 @@ cse_insn (insn, libcall_insn) insn = new; } else - /* Otherwise, force rerecognition, since it probably had - a different pattern before. - This shouldn't really be necessary, since whatever - changed the source value above should have done this. - Until the right place is found, might as well do this here. */ INSN_CODE (insn) = -1; never_reached_warning (insn); |