diff options
Diffstat (limited to 'gcc/combine.c')
| -rw-r--r-- | gcc/combine.c | 72 |
1 files changed, 20 insertions, 52 deletions
diff --git a/gcc/combine.c b/gcc/combine.c index dd01706..a36ee03 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -1065,8 +1065,6 @@ can_combine_p (insn, i3, pred, succ, pdest, psrc) /* Don't eliminate a store in the stack pointer. */ if (dest == stack_pointer_rtx - /* If we couldn't eliminate a field assignment, we can't combine. */ - || GET_CODE (dest) == ZERO_EXTRACT || GET_CODE (dest) == STRICT_LOW_PART /* Don't combine with an insn that sets a register to itself if it has a REG_EQUAL note. This may be part of a REG_NO_CONFLICT sequence. */ || (rtx_equal_p (src, dest) && find_reg_note (insn, REG_EQUAL, NULL_RTX)) @@ -1319,46 +1317,16 @@ combinable_i3pat (i3, loc, i2dest, i1dest, i1_not_in_src, pi3dest_killed) if (GET_CODE (x) == SET) { - rtx set = expand_field_assignment (x); + rtx set = x ; rtx dest = SET_DEST (set); rtx src = SET_SRC (set); rtx inner_dest = dest; -#if 0 - rtx inner_src = src; -#endif - - SUBST (*loc, set); - while (GET_CODE (inner_dest) == STRICT_LOW_PART || GET_CODE (inner_dest) == SUBREG || GET_CODE (inner_dest) == ZERO_EXTRACT) inner_dest = XEXP (inner_dest, 0); - /* We probably don't need this any more now that LIMIT_RELOAD_CLASS - was added. */ -#if 0 - while (GET_CODE (inner_src) == STRICT_LOW_PART - || GET_CODE (inner_src) == SUBREG - || GET_CODE (inner_src) == ZERO_EXTRACT) - inner_src = XEXP (inner_src, 0); - - /* If it is better that two different modes keep two different pseudos, - avoid combining them. This avoids producing the following pattern - on a 386: - (set (subreg:SI (reg/v:QI 21) 0) - (lshiftrt:SI (reg/v:SI 20) - (const_int 24))) - If that were made, reload could not handle the pair of - reg 20/21, since it would try to get any GENERAL_REGS - but some of them don't handle QImode. */ - - if (rtx_equal_p (inner_src, i2dest) - && GET_CODE (inner_dest) == REG - && ! MODES_TIEABLE_P (GET_MODE (i2dest), GET_MODE (inner_dest))) - return 0; -#endif - /* Check for the case where I3 modifies its output, as discussed above. */ if ((inner_dest != dest @@ -1689,7 +1657,7 @@ try_combine (i3, i2, i1, new_direct_jump_p) abort (); lo &= ~(UWIDE_SHIFT_LEFT_BY_BITS_PER_WORD (1) - 1); - lo |= (INTVAL (SET_SRC (PATTERN (i3))) + lo |= (INTVAL (SET_SRC (PATTERN (i3))) & (UWIDE_SHIFT_LEFT_BY_BITS_PER_WORD (1) - 1)); } else if (HOST_BITS_PER_WIDE_INT == BITS_PER_WORD) @@ -2856,7 +2824,7 @@ try_combine (i3, i2, i1, new_direct_jump_p) || GET_CODE (temp) != BARRIER) emit_barrier_after (undobuf.other_insn); } - + /* An NOOP jump does not need barrier, but it does need cleaning up of CFG. */ if (GET_CODE (newpat) == SET @@ -4044,7 +4012,7 @@ combine_simplify_rtx (x, op0_mode, last, in_dest) return gen_binary (MINUS, mode, temp, XEXP (XEXP (x, 0), 1)); } - /* (neg (mult A B)) becomes (mult (neg A) B). + /* (neg (mult A B)) becomes (mult (neg A) B). This works even for floating-point values. */ if (GET_CODE (XEXP (x, 0)) == MULT) { @@ -4185,14 +4153,14 @@ combine_simplify_rtx (x, op0_mode, last, in_dest) && GET_MODE (XEXP (XEXP (x, 0), 0)) == mode) return XEXP (XEXP (x, 0), 0); - /* (float_truncate:SF (float_truncate:DF foo:XF)) - = (float_truncate:SF foo:XF). + /* (float_truncate:SF (float_truncate:DF foo:XF)) + = (float_truncate:SF foo:XF). This may elliminate double rounding, so it is unsafe. - (float_truncate:SF (float_extend:XF foo:DF)) - = (float_truncate:SF foo:DF). + (float_truncate:SF (float_extend:XF foo:DF)) + = (float_truncate:SF foo:DF). - (float_truncate:DF (float_extend:XF foo:SF)) + (float_truncate:DF (float_extend:XF foo:SF)) = (float_extend:SF foo:DF). */ if ((GET_CODE (XEXP (x, 0)) == FLOAT_TRUNCATE && flag_unsafe_math_optimizations) @@ -4233,9 +4201,9 @@ combine_simplify_rtx (x, op0_mode, last, in_dest) break; case FLOAT_EXTEND: /* (float_extend (float_extend x)) is (float_extend x) - + (float_extend (float x)) is (float x) assuming that double - rounding can't happen. + rounding can't happen. */ if (GET_CODE (XEXP (x, 0)) == FLOAT_EXTEND || (GET_CODE (XEXP (x, 0)) == FLOAT @@ -4288,11 +4256,11 @@ combine_simplify_rtx (x, op0_mode, last, in_dest) case PLUS: /* Canonicalize (plus (mult (neg B) C) A) to (minus A (mult B C)). */ - if (GET_CODE (XEXP (x, 0)) == MULT + if (GET_CODE (XEXP (x, 0)) == MULT && GET_CODE (XEXP (XEXP (x, 0), 0)) == NEG) { rtx in1, in2; - + in1 = XEXP (XEXP (XEXP (x, 0), 0), 0); in2 = XEXP (XEXP (x, 0), 1); return gen_binary (MINUS, mode, XEXP (x, 1), @@ -4407,24 +4375,24 @@ combine_simplify_rtx (x, op0_mode, last, in_dest) /* Canonicalize (minus A (mult (neg B) C)) to (plus (mult B C) A). */ - if (GET_CODE (XEXP (x, 1)) == MULT + if (GET_CODE (XEXP (x, 1)) == MULT && GET_CODE (XEXP (XEXP (x, 1), 0)) == NEG) { rtx in1, in2; - + in1 = XEXP (XEXP (XEXP (x, 1), 0), 0); in2 = XEXP (XEXP (x, 1), 1); return gen_binary (PLUS, mode, gen_binary (MULT, mode, in1, in2), XEXP (x, 0)); } - /* Canonicalize (minus (neg A) (mult B C)) to + /* Canonicalize (minus (neg A) (mult B C)) to (minus (mult (neg B) C) A). */ - if (GET_CODE (XEXP (x, 1)) == MULT + if (GET_CODE (XEXP (x, 1)) == MULT && GET_CODE (XEXP (x, 0)) == NEG) { rtx in1, in2; - + in1 = simplify_gen_unary (NEG, mode, XEXP (XEXP (x, 1), 0), mode); in2 = XEXP (XEXP (x, 1), 1); return gen_binary (MINUS, mode, gen_binary (MULT, mode, in1, in2), @@ -5313,7 +5281,7 @@ simplify_set (x) #ifdef CANNOT_CHANGE_MODE_CLASS && ! (GET_CODE (dest) == REG && REGNO (dest) < FIRST_PSEUDO_REGISTER && REG_CANNOT_CHANGE_MODE_P (REGNO (dest), - GET_MODE (SUBREG_REG (src)), + GET_MODE (SUBREG_REG (src)), GET_MODE (src))) #endif && (GET_CODE (dest) == REG @@ -11594,7 +11562,7 @@ update_table_tick (x) break; } } - + update_table_tick (XEXP (x, i)); } } |