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author | Richard Sandiford <rdsandiford@googlemail.com> | 2014-08-28 06:23:42 +0000 |
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committer | Richard Sandiford <rsandifo@gcc.gnu.org> | 2014-08-28 06:23:42 +0000 |
commit | 4ca29addfc97aa04a3da082840ea0c7bf5dedb18 (patch) | |
tree | d97aa2672cc5b80f8c75c47fbfeb1a30d1fc385a /gcc/loop-iv.c | |
parent | e7c44276618b5ee91df8eb2f9bdd3e4a79829226 (diff) | |
download | gcc-4ca29addfc97aa04a3da082840ea0c7bf5dedb18.zip gcc-4ca29addfc97aa04a3da082840ea0c7bf5dedb18.tar.gz gcc-4ca29addfc97aa04a3da082840ea0c7bf5dedb18.tar.bz2 |
loop-iv.c: Include rtl-iter.h.
gcc/
* loop-iv.c: Include rtl-iter.h.
(find_single_def_src): New function.
(replace_single_def_regs): Turn from being a for_each_rtx callback
to being a function that examines each subrtx itself.
(replace_in_expr, simplify_using_initial_values): Update accordingly.
From-SVN: r214645
Diffstat (limited to 'gcc/loop-iv.c')
-rw-r--r-- | gcc/loop-iv.c | 53 |
1 files changed, 32 insertions, 21 deletions
diff --git a/gcc/loop-iv.c b/gcc/loop-iv.c index eb3fd47..b8f5e12 100644 --- a/gcc/loop-iv.c +++ b/gcc/loop-iv.c @@ -62,6 +62,7 @@ along with GCC; see the file COPYING3. If not see #include "df.h" #include "hash-table.h" #include "dumpfile.h" +#include "rtl-iter.h" /* Possible return values of iv_get_reaching_def. */ @@ -1398,33 +1399,27 @@ simple_rhs_p (rtx rhs) } } -/* If REG has a single definition, replace it with its known value in EXPR. - Callback for for_each_rtx. */ +/* If REGNO has a single definition, return its known value, otherwise return + null. */ -static int -replace_single_def_regs (rtx *reg, void *expr1) +static rtx +find_single_def_src (unsigned int regno) { - unsigned regno; df_ref adef; rtx set, src; - rtx *expr = (rtx *)expr1; - - if (!REG_P (*reg)) - return 0; - regno = REGNO (*reg); for (;;) { rtx note; adef = DF_REG_DEF_CHAIN (regno); if (adef == NULL || DF_REF_NEXT_REG (adef) != NULL - || DF_REF_IS_ARTIFICIAL (adef)) - return -1; + || DF_REF_IS_ARTIFICIAL (adef)) + return NULL_RTX; set = single_set (DF_REF_INSN (adef)); if (set == NULL || !REG_P (SET_DEST (set)) || REGNO (SET_DEST (set)) != regno) - return -1; + return NULL_RTX; note = find_reg_equal_equiv_note (DF_REF_INSN (adef)); @@ -1443,10 +1438,29 @@ replace_single_def_regs (rtx *reg, void *expr1) break; } if (!function_invariant_p (src)) - return -1; + return NULL_RTX; - *expr = simplify_replace_rtx (*expr, *reg, src); - return 1; + return src; +} + +/* If any registers in *EXPR that have a single definition, try to replace + them with the known-equivalent values. */ + +static void +replace_single_def_regs (rtx *expr) +{ + subrtx_var_iterator::array_type array; + repeat: + FOR_EACH_SUBRTX_VAR (iter, array, *expr, NONCONST) + { + rtx x = *iter; + if (REG_P (x)) + if (rtx new_x = find_single_def_src (REGNO (x))) + { + *expr = simplify_replace_rtx (*expr, x, new_x); + goto repeat; + } + } } /* A subroutine of simplify_using_initial_values, this function examines INSN @@ -1491,8 +1505,7 @@ replace_in_expr (rtx *expr, rtx dest, rtx src) *expr = simplify_replace_rtx (*expr, dest, src); if (old == *expr) return; - while (for_each_rtx (expr, replace_single_def_regs, expr) != 0) - continue; + replace_single_def_regs (expr); } /* Checks whether A implies B. */ @@ -1937,9 +1950,7 @@ simplify_using_initial_values (struct loop *loop, enum rtx_code op, rtx *expr) gcc_assert (op == UNKNOWN); - for (;;) - if (for_each_rtx (expr, replace_single_def_regs, expr) == 0) - break; + replace_single_def_regs (expr); if (CONSTANT_P (*expr)) return; |