diff options
Diffstat (limited to 'gcc/cse.c')
| -rw-r--r-- | gcc/cse.c | 23 |
1 files changed, 17 insertions, 6 deletions
@@ -43,6 +43,7 @@ along with GCC; see the file COPYING3. If not see #include "tree-pass.h" #include "df.h" #include "dbgcnt.h" +#include "pointer-set.h" /* The basic idea of common subexpression elimination is to go through the code, keeping a record of expressions that would @@ -2897,6 +2898,9 @@ find_comparison_args (enum rtx_code code, rtx *parg1, rtx *parg2, enum machine_mode *pmode1, enum machine_mode *pmode2) { rtx arg1, arg2; + struct pointer_set_t *visited = NULL; + /* Set nonzero when we find something of interest. */ + rtx x = NULL; arg1 = *parg1, arg2 = *parg2; @@ -2904,11 +2908,18 @@ find_comparison_args (enum rtx_code code, rtx *parg1, rtx *parg2, while (arg2 == CONST0_RTX (GET_MODE (arg1))) { - /* Set nonzero when we find something of interest. */ - rtx x = 0; int reverse_code = 0; struct table_elt *p = 0; + /* Remember state from previous iteration. */ + if (x) + { + if (!visited) + visited = pointer_set_create (); + pointer_set_insert (visited, x); + x = 0; + } + /* If arg1 is a COMPARE, extract the comparison arguments from it. On machines with CC0, this is the only case that can occur, since fold_rtx will return the COMPARE or item being compared with zero @@ -2985,10 +2996,8 @@ find_comparison_args (enum rtx_code code, rtx *parg1, rtx *parg2, if (! exp_equiv_p (p->exp, p->exp, 1, false)) continue; - /* If it's the same comparison we're already looking at, skip it. */ - if (COMPARISON_P (p->exp) - && XEXP (p->exp, 0) == arg1 - && XEXP (p->exp, 1) == arg2) + /* If it's a comparison we've used before, skip it. */ + if (visited && pointer_set_contains (visited, p->exp)) continue; if (GET_CODE (p->exp) == COMPARE @@ -3069,6 +3078,8 @@ find_comparison_args (enum rtx_code code, rtx *parg1, rtx *parg2, *pmode1 = GET_MODE (arg1), *pmode2 = GET_MODE (arg2); *parg1 = fold_rtx (arg1, 0), *parg2 = fold_rtx (arg2, 0); + if (visited) + pointer_set_destroy (visited); return code; } |