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| author | Richard Biener <rguenther@suse.de> | 2016-08-12 12:58:15 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2016-08-12 12:58:15 +0000 |
| commit | e373dd067e6f29cd333cddd741611f5979718c58 (patch) | |
| tree | 9f4ca179884496904f5a175a84357487283ad659 /gcc/tree-ssa-pre.c | |
| parent | 20d1af89b40d0a939a7afefeecf6652bd587e18b (diff) | |
| download | gcc-e373dd067e6f29cd333cddd741611f5979718c58.zip gcc-e373dd067e6f29cd333cddd741611f5979718c58.tar.gz gcc-e373dd067e6f29cd333cddd741611f5979718c58.tar.bz2 | |
re PR tree-optimization/57326 (Piecewise folding of operations on PHI nodes)
2016-08-12 Richard Biener <rguenther@suse.de>
PR tree-optimization/57326
* tree-ssa-pre.c (fully_constant_expression): Handle simplification
returning an SSA name.
(phi_translate_1): When fully_constant_expression returns a NAME
make sure we have a leader for it.
* gcc.dg/tree-ssa/ssa-pre-32.c: New testcase.
* gcc.dg/tree-ssa/loadpre14.c: Adjust.
* gcc.dg/tree-ssa/pr35287.c: Likewise.
* gcc.target/i386/pr45685.c: Likewise.
* gcc.dg/tree-ssa/predcom-1.c: Disable PRE.
* gcc.dg/tree-ssa/predcom-2.c: Likewise.
* gcc.dg/tree-ssa/predcom-3.c: Likewise.
* gcc.dg/tree-ssa/ssa-sink-10.c: Likewise.
* gfortran.dg/pr34163.f90: Likewise.
From-SVN: r239414
Diffstat (limited to 'gcc/tree-ssa-pre.c')
| -rw-r--r-- | gcc/tree-ssa-pre.c | 23 |
1 files changed, 17 insertions, 6 deletions
diff --git a/gcc/tree-ssa-pre.c b/gcc/tree-ssa-pre.c index c2c7495..edc3fdf 100644 --- a/gcc/tree-ssa-pre.c +++ b/gcc/tree-ssa-pre.c @@ -1201,7 +1201,7 @@ get_or_alloc_expr_for (tree t) } /* Return the folded version of T if T, when folded, is a gimple - min_invariant. Otherwise, return T. */ + min_invariant or an SSA name. Otherwise, return T. */ static pre_expr fully_constant_expression (pre_expr e) @@ -1218,10 +1218,8 @@ fully_constant_expression (pre_expr e) return e; if (is_gimple_min_invariant (res)) return get_or_alloc_expr_for_constant (res); - /* We might have simplified the expression to a - SSA_NAME for example from x_1 * 1. But we cannot - insert a PHI for x_1 unconditionally as x_1 might - not be available readily. */ + if (TREE_CODE (res) == SSA_NAME) + return get_or_alloc_expr_for_name (res); return e; } case REFERENCE: @@ -1464,7 +1462,20 @@ phi_translate_1 (pre_expr expr, bitmap_set_t set1, bitmap_set_t set2, constant = fully_constant_expression (expr); PRE_EXPR_NARY (expr) = nary; if (constant != expr) - return constant; + { + /* For non-CONSTANTs we have to make sure we can eventually + insert the expression. Which means we need to have a + leader for it. */ + if (constant->kind != CONSTANT) + { + unsigned value_id = get_expr_value_id (constant); + constant = find_leader_in_sets (value_id, set1, set2); + if (constant) + return constant; + } + else + return constant; + } tree result = vn_nary_op_lookup_pieces (newnary->length, newnary->opcode, |