diff options
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/pr20913.c | 25 | ||||
| -rw-r--r-- | gcc/tree-ssa-copy.c | 13 |
4 files changed, 45 insertions, 3 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 1a5f5f85d90..3d0636cc6f8 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2005-04-13 Kazu Hirata <kazu@cs.umass.edu> + + PR tree-optimization/20913 + * tree-ssa-copy.c (copy_prop_visit_cond_stmt): Fold COND_EXPR. + 2005-04-13 Julian Brown <julian@codesourcery.com> * config/elfos.h (MAKE_DECL_ONE_ONLY): Redefined to stop DECL_WEAK from diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index de9f91137ca..6faba54bdb0 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2005-04-13 Kazu Hirata <kazu@cs.umass.edu> + + PR tree-optimization/20913 + * gcc.dg/tree-ssa/pr20913.c: New. + 2005-04-13 Volker Reichelt <reichelt@igpm.rwth-aachen.de> PR c++/13744 diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr20913.c b/gcc/testsuite/gcc.dg/tree-ssa/pr20913.c new file mode 100644 index 00000000000..da09183bee3 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr20913.c @@ -0,0 +1,25 @@ +/* PR tree-optimization/20913 + COPY-PROP did not fold COND_EXPR, blocking some copy propagation + opportunities. */ + +/* { dg-do compile } */ +/* { dg-options "-O2 -fno-tree-dominator-opts -fdump-tree-copyprop1-details" } */ + +int +foo (int a, int b, int c, int d) +{ + int x, y; + + b = a; + if (a == b) + x = c; + else + x = d; + + if (x == c) + return a; + else + return b; +} + +/* { dg-final { scan-tree-dump-times "with if \\(1\\)" 2 "copyprop1"} } */ diff --git a/gcc/tree-ssa-copy.c b/gcc/tree-ssa-copy.c index 91d80a7aef9..b9544f88979 100644 --- a/gcc/tree-ssa-copy.c +++ b/gcc/tree-ssa-copy.c @@ -626,9 +626,16 @@ copy_prop_visit_cond_stmt (tree stmt, edge *taken_edge_p) print_generic_stmt (dump_file, cond, 0); } - *taken_edge_p = find_taken_edge (bb_for_stmt (stmt), cond); - if (*taken_edge_p) - retval = SSA_PROP_INTERESTING; + /* We can fold COND only and get a useful result only when we + have the same SSA_NAME on both sides of a comparison + operator. */ + if (TREE_CODE (TREE_OPERAND (cond, 0)) == SSA_NAME + && TREE_OPERAND (cond, 0) == TREE_OPERAND (cond, 1)) + { + *taken_edge_p = find_taken_edge (bb_for_stmt (stmt), fold (cond)); + if (*taken_edge_p) + retval = SSA_PROP_INTERESTING; + } /* Restore the original operands. */ for (i = 0; i < NUM_USES (uses); i++) |