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| author | Kazu Hirata <kazu@cs.umass.edu> | 2004-03-25 16:16:41 +0000 |
|---|---|---|
| committer | Kazu Hirata <kazu@gcc.gnu.org> | 2004-03-25 16:16:41 +0000 |
| commit | 43a21dfc46151a5f50f7372fda42b6eba36950c9 (patch) | |
| tree | b8180448c0f7c82d4935723ff1e395c1211301e7 /gcc | |
| parent | 6d11af89b1c8723f644edcd243ba109b0cb2507d (diff) | |
| download | gcc-43a21dfc46151a5f50f7372fda42b6eba36950c9.zip gcc-43a21dfc46151a5f50f7372fda42b6eba36950c9.tar.gz gcc-43a21dfc46151a5f50f7372fda42b6eba36950c9.tar.bz2 | |
re PR middle-end/9707 (Unnecessary range test in switches with less than 4 cases)
PR optimization/9707.
* stmt.c (emit_case_nodes): Emit equality comparisons instead
of recursing if both children are single-valued cases with no
children.
From-SVN: r79954
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 7 | ||||
| -rw-r--r-- | gcc/stmt.c | 36 |
2 files changed, 43 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 505adac..e63bbff 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2004-03-25 Kazu Hirata <kazu@cs.umass.edu> + + PR optimization/9707. + * stmt.c (emit_case_nodes): Emit equality comparisons instead + of recursing if both children are single-valued cases with no + children. + 2004-03-25 Paul Brook <paul@codesourcery.com> * config/arm/arm.c (vfp_print_multi): Remove. @@ -6200,6 +6200,42 @@ emit_case_nodes (rtx index, case_node_ptr node, rtx default_label, emit_case_nodes (index, node->right, default_label, index_type); } + /* If both children are single-valued cases with no + children, finish up all the work. This way, we can save + one ordered comparison. */ + else if (tree_int_cst_equal (node->right->low, node->right->high) + && node->right->left == 0 + && node->right->right == 0 + && tree_int_cst_equal (node->left->low, node->left->high) + && node->left->left == 0 + && node->left->right == 0) + { + /* Neither node is bounded. First distinguish the two sides; + then emit the code for one side at a time. */ + + /* See if the value matches what the right hand side + wants. */ + do_jump_if_equal (index, + convert_modes (mode, imode, + expand_expr (node->right->low, + NULL_RTX, + VOIDmode, 0), + unsignedp), + label_rtx (node->right->code_label), + unsignedp); + + /* See if the value matches what the left hand side + wants. */ + do_jump_if_equal (index, + convert_modes (mode, imode, + expand_expr (node->left->low, + NULL_RTX, + VOIDmode, 0), + unsignedp), + label_rtx (node->left->code_label), + unsignedp); + } + else { /* Neither node is bounded. First distinguish the two sides; |