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| author | Bill Schmidt <wschmidt@linux.vnet.ibm.com> | 2018-01-02 22:56:45 +0000 |
|---|---|---|
| committer | William Schmidt <wschmidt@gcc.gnu.org> | 2018-01-02 22:56:45 +0000 |
| commit | 6012c652c778abaf9fb07fb1628435ff055dd349 (patch) | |
| tree | 9c7959f41fe324a28bdfa3591a853985afeee38f /gcc/config | |
| parent | f1bdc63a898f2fa164e79528c03e96a21a779e82 (diff) | |
| download | gcc-6012c652c778abaf9fb07fb1628435ff055dd349.zip gcc-6012c652c778abaf9fb07fb1628435ff055dd349.tar.gz gcc-6012c652c778abaf9fb07fb1628435ff055dd349.tar.bz2 | |
rs6000-p8swap.c (swap_feeds_both_load_and_store): New function.
2018-01-02 Bill Schmidt <wschmidt@linux.vnet.ibm.com>
* config/rs6000/rs6000-p8swap.c (swap_feeds_both_load_and_store):
New function.
(rs6000_analyze_swaps): Mark a web unoptimizable if it contains a
swap associated with both a load and a store.
From-SVN: r256111
Diffstat (limited to 'gcc/config')
| -rw-r--r-- | gcc/config/rs6000/rs6000-p8swap.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/gcc/config/rs6000/rs6000-p8swap.c b/gcc/config/rs6000/rs6000-p8swap.c index e0d8f31..5a97116 100644 --- a/gcc/config/rs6000/rs6000-p8swap.c +++ b/gcc/config/rs6000/rs6000-p8swap.c @@ -328,6 +328,38 @@ insn_is_swap_p (rtx insn) return 1; } +/* Return 1 iff UID, known to reference a swap, is both fed by a load + and a feeder of a store. */ +static unsigned int +swap_feeds_both_load_and_store (swap_web_entry *insn_entry) +{ + rtx insn = insn_entry->insn; + struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn); + df_ref def, use; + struct df_link *link = 0; + rtx_insn *load = 0, *store = 0; + bool fed_by_load = 0; + bool feeds_store = 0; + + FOR_EACH_INSN_INFO_USE (use, insn_info) + { + link = DF_REF_CHAIN (use); + load = DF_REF_INSN (link->ref); + if (insn_is_load_p (load) && insn_is_swap_p (load)) + fed_by_load = 1; + } + + FOR_EACH_INSN_INFO_DEF (def, insn_info) + { + link = DF_REF_CHAIN (def); + store = DF_REF_INSN (link->ref); + if (insn_is_store_p (store) && insn_is_swap_p (store)) + feeds_store = 1; + } + + return fed_by_load && feeds_store; +} + /* Return TRUE if insn is a swap fed by a load from the constant pool. */ static bool const_load_sequence_p (swap_web_entry *insn_entry, rtx insn) @@ -2030,6 +2062,14 @@ rs6000_analyze_swaps (function *fun) && !insn_entry[i].is_swap && !insn_entry[i].is_swappable) root->web_not_optimizable = 1; + /* If we have a swap that is both fed by a permuting load + and a feeder of a permuting store, then the optimization + isn't appropriate. (Consider vec_xl followed by vec_xst_be.) */ + else if (insn_entry[i].is_swap && !insn_entry[i].is_load + && !insn_entry[i].is_store + && swap_feeds_both_load_and_store (&insn_entry[i])) + root->web_not_optimizable = 1; + /* If we have permuting loads or stores that are not accompanied by a register swap, the optimization isn't appropriate. */ else if (insn_entry[i].is_load && insn_entry[i].is_swap) |