diff options
Diffstat (limited to 'gcc/ccmp.c')
| -rw-r--r-- | gcc/ccmp.c | 21 |
1 files changed, 14 insertions, 7 deletions
@@ -49,6 +49,10 @@ along with GCC; see the file COPYING3. If not see - gen_ccmp_first expands the first compare in CCMP. - gen_ccmp_next expands the following compares. + Both hooks return a comparison with the CC register that is equivalent + to the value of the gimple comparison. This is used by the next CCMP + and in the final conditional store. + * We use cstorecc4 pattern to convert the CCmode intermediate to the integer mode result that expand_normal is expecting. @@ -114,10 +118,12 @@ ccmp_candidate_p (gimple *g) return false; } -/* PREV is the CC flag from precvious compares. The function expands the - next compare based on G which ops previous compare with CODE. +/* PREV is a comparison with the CC register which represents the + result of the previous CMP or CCMP. The function expands the + next compare based on G which is ANDed/ORed with the previous + compare depending on CODE. PREP_SEQ returns all insns to prepare opearands for compare. - GEN_SEQ returnss all compare insns. */ + GEN_SEQ returns all compare insns. */ static rtx expand_ccmp_next (gimple *g, enum tree_code code, rtx prev, rtx *prep_seq, rtx *gen_seq) @@ -210,7 +216,7 @@ expand_ccmp_expr_1 (gimple *g, rtx *prep_seq, rtx *gen_seq) return NULL_RTX; } -/* Main entry to expand conditional compare statement G. +/* Main entry to expand conditional compare statement G. Return NULL_RTX if G is not a legal candidate or expand fail. Otherwise return the target. */ rtx @@ -233,9 +239,10 @@ expand_ccmp_expr (gimple *g) enum insn_code icode; enum machine_mode cc_mode = CCmode; tree lhs = gimple_assign_lhs (g); + rtx_code cmp_code = GET_CODE (tmp); #ifdef SELECT_CC_MODE - cc_mode = SELECT_CC_MODE (NE, tmp, const0_rtx); + cc_mode = SELECT_CC_MODE (cmp_code, XEXP (tmp, 0), const0_rtx); #endif icode = optab_handler (cstore_optab, cc_mode); if (icode != CODE_FOR_nothing) @@ -246,8 +253,8 @@ expand_ccmp_expr (gimple *g) emit_insn (prep_seq); emit_insn (gen_seq); - tmp = emit_cstore (target, icode, NE, cc_mode, cc_mode, - 0, tmp, const0_rtx, 1, mode); + tmp = emit_cstore (target, icode, cmp_code, cc_mode, cc_mode, + 0, XEXP (tmp, 0), const0_rtx, 1, mode); if (tmp) return tmp; } |