diff options
Diffstat (limited to 'contrib/gcc/combine.c')
| -rw-r--r-- | contrib/gcc/combine.c | 59 |
1 files changed, 48 insertions, 11 deletions
diff --git a/contrib/gcc/combine.c b/contrib/gcc/combine.c index 03d0dffa6baf..cec5a29cf511 100644 --- a/contrib/gcc/combine.c +++ b/contrib/gcc/combine.c @@ -424,6 +424,7 @@ static int insn_cuid PARAMS ((rtx)); static void record_promoted_value PARAMS ((rtx, rtx)); static rtx reversed_comparison PARAMS ((rtx, enum machine_mode, rtx, rtx)); static enum rtx_code combine_reversed_comparison_code PARAMS ((rtx)); +static void adjust_for_new_dest PARAMS ((rtx)); /* Substitute NEWVAL, an rtx expression, into INTO, a place in some insn. The substitution can be undone by undo_all. If INTO is already @@ -1502,6 +1503,34 @@ cant_combine_insn_p (insn) return 0; } +/* Adjust INSN after we made a change to its destination. + + Changing the destination can invalidate notes that say something about + the results of the insn and a LOG_LINK pointing to the insn. */ + +static void +adjust_for_new_dest (insn) + rtx insn; +{ + rtx *loc; + + /* For notes, be conservative and simply remove them. */ + loc = ®_NOTES (insn); + while (*loc) + { + enum reg_note kind = REG_NOTE_KIND (*loc); + if (kind == REG_EQUAL || kind == REG_EQUIV) + *loc = XEXP (*loc, 1); + else + loc = &XEXP (*loc, 1); + } + + /* The new insn will have a destination that was previously the destination + of an insn just above it. Call distribute_links to make a LOG_LINK from + the next use of that destination. */ + distribute_links (gen_rtx_INSN_LIST (VOIDmode, insn, NULL_RTX)); +} + /* Try to combine the insns I1 and I2 into I3. Here I1 and I2 appear earlier than I3. I1 can be zero; then we combine just I2 into I3. @@ -2124,6 +2153,14 @@ try_combine (i3, i2, i1, new_direct_jump_p) { newpat = XVECEXP (newpat, 0, 1); insn_code_number = recog_for_combine (&newpat, i3, &new_i3_notes); + + if (insn_code_number >= 0) + { + /* If we will be able to accept this, we have made a change to the + destination of I3. This requires us to do a few adjustments. */ + PATTERN (i3) = newpat; + adjust_for_new_dest (i3); + } } /* If we were combining three insns and the result is a simple SET @@ -2394,16 +2431,9 @@ try_combine (i3, i2, i1, new_direct_jump_p) rtx link; /* If we will be able to accept this, we have made a change to the - destination of I3. This can invalidate a LOG_LINKS pointing - to I3. No other part of combine.c makes such a transformation. - - The new I3 will have a destination that was previously the - destination of I1 or I2 and which was used in i2 or I3. Call - distribute_links to make a LOG_LINK from the next use of - that destination. */ - + destination of I3. This requires us to do a few adjustments. */ PATTERN (i3) = newpat; - distribute_links (gen_rtx_INSN_LIST (VOIDmode, i3, NULL_RTX)); + adjust_for_new_dest (i3); /* I3 now uses what used to be its destination and which is now I2's destination. That means we need a LOG_LINK from @@ -7812,6 +7842,7 @@ make_field_assignment (x) && (GET_MODE_SIZE (GET_MODE (XEXP (src, 0))) < GET_MODE_SIZE (GET_MODE (SUBREG_REG (XEXP (src, 0))))) && GET_CODE (SUBREG_REG (XEXP (src, 0))) == ROTATE + && GET_CODE (XEXP (SUBREG_REG (XEXP (src, 0)), 0)) == CONST_INT && INTVAL (XEXP (SUBREG_REG (XEXP (src, 0)), 0)) == -2 && rtx_equal_for_field_assignment_p (dest, XEXP (src, 1))) { @@ -10209,6 +10240,11 @@ gen_binary (code, mode, op0, op1) rtx result; rtx tem; + if (GET_CODE (op0) == CLOBBER) + return op0; + else if (GET_CODE (op1) == CLOBBER) + return op1; + if (GET_RTX_CLASS (code) == 'c' && swap_commutative_operands_p (op0, op1)) tem = op0, op0 = op1, op1 = tem; @@ -12569,6 +12605,7 @@ distribute_notes (notes, from_insn, i3, i2, elim_i2, elim_i1) abort (); break; + case REG_ALWAYS_RETURN: case REG_NORETURN: case REG_SETJMP: /* These notes must remain with the call. It should not be @@ -13070,8 +13107,8 @@ distribute_notes (notes, from_insn, i3, i2, elim_i2, elim_i1) } /* Similarly to above, distribute the LOG_LINKS that used to be present on - I3, I2, and I1 to new locations. This is also called in one case to - add a link pointing at I3 when I3's destination is changed. */ + I3, I2, and I1 to new locations. This is also called to add a link + pointing at I3 when I3's destination is changed. */ static void distribute_links (links) |