diff options
Diffstat (limited to 'gcc/explow.c')
| -rw-r--r-- | gcc/explow.c | 77 |
1 files changed, 46 insertions, 31 deletions
diff --git a/gcc/explow.c b/gcc/explow.c index 11dffed..ff26dbf 100644 --- a/gcc/explow.c +++ b/gcc/explow.c @@ -74,14 +74,20 @@ trunc_int_for_mode (HOST_WIDE_INT c, enum machine_mode mode) return c; } -/* Return an rtx for the sum of X and the integer C. */ +/* Return an rtx for the sum of X and the integer C, given that X has + mode MODE. This routine should be used instead of plus_constant + when they want to ensure that addition happens in a particular + mode, which is necessary when X can be a VOIDmode CONST_INT or + CONST_DOUBLE and the width of the constant is different from the + width of the expression. */ +/* TODO: All callers of plus_constant should migrate to this routine, + and once they do, we can assert that mode is not VOIDmode. */ rtx -plus_constant (rtx x, HOST_WIDE_INT c) +plus_constant_mode (enum machine_mode mode, rtx x, HOST_WIDE_INT c) { RTX_CODE code; rtx y; - enum machine_mode mode; rtx tem; int all_constant = 0; @@ -91,12 +97,26 @@ plus_constant (rtx x, HOST_WIDE_INT c) restart: code = GET_CODE (x); - mode = GET_MODE (x); y = x; switch (code) { case CONST_INT: + if (GET_MODE_BITSIZE (mode) > HOST_BITS_PER_WIDE_INT) + { + unsigned HOST_WIDE_INT l1 = INTVAL (x); + HOST_WIDE_INT h1 = (l1 >> (HOST_BITS_PER_WIDE_INT - 1)) ? -1 : 0; + unsigned HOST_WIDE_INT l2 = c; + HOST_WIDE_INT h2 = c < 0 ? -1 : 0; + unsigned HOST_WIDE_INT lv; + HOST_WIDE_INT hv; + + if (add_double_with_sign (l1, h1, l2, h2, &lv, &hv, false)) + gcc_unreachable (); + + return immed_double_const (lv, hv, VOIDmode); + } + return GEN_INT (INTVAL (x) + c); case CONST_DOUBLE: @@ -104,11 +124,14 @@ plus_constant (rtx x, HOST_WIDE_INT c) unsigned HOST_WIDE_INT l1 = CONST_DOUBLE_LOW (x); HOST_WIDE_INT h1 = CONST_DOUBLE_HIGH (x); unsigned HOST_WIDE_INT l2 = c; - HOST_WIDE_INT h2 = c < 0 ? ~0 : 0; + HOST_WIDE_INT h2 = c < 0 ? -1 : 0; unsigned HOST_WIDE_INT lv; HOST_WIDE_INT hv; - add_double (l1, h1, l2, h2, &lv, &hv); + if (add_double_with_sign (l1, h1, l2, h2, &lv, &hv, false)) + /* Sorry, we have no way to represent overflows this wide. + To fix, add constant support wider than CONST_DOUBLE. */ + gcc_assert (GET_MODE_BITSIZE (mode) <= 2 * HOST_BITS_PER_WIDE_INT); return immed_double_const (lv, hv, VOIDmode); } @@ -120,10 +143,8 @@ plus_constant (rtx x, HOST_WIDE_INT c) if (GET_CODE (XEXP (x, 0)) == SYMBOL_REF && CONSTANT_POOL_ADDRESS_P (XEXP (x, 0))) { - tem - = force_const_mem (GET_MODE (x), - plus_constant (get_pool_constant (XEXP (x, 0)), - c)); + tem = plus_constant_mode (mode, get_pool_constant (XEXP (x, 0)), c); + tem = force_const_mem (GET_MODE (x), tem); if (memory_address_p (GET_MODE (tem), XEXP (tem, 0))) return tem; } @@ -142,31 +163,17 @@ plus_constant (rtx x, HOST_WIDE_INT c) break; case PLUS: - /* The interesting case is adding the integer to a sum. - Look for constant term in the sum and combine - with C. For an integer constant term, we make a combined - integer. For a constant term that is not an explicit integer, - we cannot really combine, but group them together anyway. - - Restart or use a recursive call in case the remaining operand is - something that we handle specially, such as a SYMBOL_REF. + /* The interesting case is adding the integer to a sum. Look + for constant term in the sum and combine with C. For an + integer constant term or a constant term that is not an + explicit integer, we combine or group them together anyway. We may not immediately return from the recursive call here, lest all_constant gets lost. */ - if (CONST_INT_P (XEXP (x, 1))) + if (CONSTANT_P (XEXP (x, 1))) { - c += INTVAL (XEXP (x, 1)); - - if (GET_MODE (x) != VOIDmode) - c = trunc_int_for_mode (c, GET_MODE (x)); - - x = XEXP (x, 0); - goto restart; - } - else if (CONSTANT_P (XEXP (x, 1))) - { - x = gen_rtx_PLUS (mode, XEXP (x, 0), plus_constant (XEXP (x, 1), c)); + x = gen_rtx_PLUS (mode, XEXP (x, 0), plus_constant_mode (mode, XEXP (x, 1), c)); c = 0; } else if (find_constant_term_loc (&y)) @@ -176,7 +183,7 @@ plus_constant (rtx x, HOST_WIDE_INT c) rtx copy = copy_rtx (x); rtx *const_loc = find_constant_term_loc (©); - *const_loc = plus_constant (*const_loc, c); + *const_loc = plus_constant_mode (mode, *const_loc, c); x = copy; c = 0; } @@ -196,6 +203,14 @@ plus_constant (rtx x, HOST_WIDE_INT c) else return x; } + +/* Return an rtx for the sum of X and the integer C. */ + +rtx +plus_constant (rtx x, HOST_WIDE_INT c) +{ + return plus_constant_mode (GET_MODE (x), x, c); +} /* If X is a sum, return a new sum like X but lacking any constant terms. Add all the removed constant terms into *CONSTPTR. |