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| author | Richard Kenner <kenner@vlsi1.ultra.nyu.edu> | 2004-11-29 01:08:41 +0000 |
|---|---|---|
| committer | Richard Kenner <kenner@gcc.gnu.org> | 2004-11-28 20:08:41 -0500 |
| commit | 9390c347e9f2ac5dc3a97933f537c1576a310f4e (patch) | |
| tree | b482d08649ec8d47fb095b9196547e3f66709af8 /gcc/tree-ssa-ccp.c | |
| parent | ab1a8620fc5bef59dec0bb8b7b41cea4132435d5 (diff) | |
| download | gcc-9390c347e9f2ac5dc3a97933f537c1576a310f4e.zip gcc-9390c347e9f2ac5dc3a97933f537c1576a310f4e.tar.gz gcc-9390c347e9f2ac5dc3a97933f537c1576a310f4e.tar.bz2 | |
tree-ssa-operands.c (build_ssa_operands, [...]): Ignore a VIEW_CONVERT_EXPR on LHS when deciding if must or may def.
PR/18664
* tree-ssa-operands.c (build_ssa_operands, case MODIFY_EXPR):
Ignore a VIEW_CONVERT_EXPR on LHS when deciding if must or may def.
* tree-ssa-ccp.c (visit_assignment): If LHS is a VIEW_CONVERT_EXPR,
add an inverse VIEW_CONVERT_EXPR to const_val.
From-SVN: r91450
Diffstat (limited to 'gcc/tree-ssa-ccp.c')
| -rw-r--r-- | gcc/tree-ssa-ccp.c | 30 |
1 files changed, 22 insertions, 8 deletions
diff --git a/gcc/tree-ssa-ccp.c b/gcc/tree-ssa-ccp.c index 31807fe..911e573 100644 --- a/gcc/tree-ssa-ccp.c +++ b/gcc/tree-ssa-ccp.c @@ -1053,21 +1053,35 @@ visit_assignment (tree stmt, tree *output_p) val = *nval; } else - { - /* Evaluate the statement. */ + /* Evaluate the statement. */ val = evaluate_stmt (stmt); - } - /* FIXME: Hack. If this was a definition of a bitfield, we need to widen + /* If the original LHS was a VIEW_CONVERT_EXPR, modify the constant + value to be a VIEW_CONVERT_EXPR of the old constant value. This is + valid because a VIEW_CONVERT_EXPR is valid everywhere an operand of + aggregate type is valid. + + ??? Also, if this was a definition of a bitfield, we need to widen the constant value into the type of the destination variable. This should not be necessary if GCC represented bitfields properly. */ { - tree lhs = TREE_OPERAND (stmt, 0); + tree orig_lhs = TREE_OPERAND (stmt, 0); + + if (TREE_CODE (orig_lhs) == VIEW_CONVERT_EXPR + && val.lattice_val == CONSTANT) + { + val.const_val = build1 (VIEW_CONVERT_EXPR, + TREE_TYPE (TREE_OPERAND (orig_lhs, 0)), + val.const_val); + orig_lhs = TREE_OPERAND (orig_lhs, 1); + } + if (val.lattice_val == CONSTANT - && TREE_CODE (lhs) == COMPONENT_REF - && DECL_BIT_FIELD (TREE_OPERAND (lhs, 1))) + && TREE_CODE (orig_lhs) == COMPONENT_REF + && DECL_BIT_FIELD (TREE_OPERAND (orig_lhs, 1))) { - tree w = widen_bitfield (val.const_val, TREE_OPERAND (lhs, 1), lhs); + tree w = widen_bitfield (val.const_val, TREE_OPERAND (orig_lhs, 1), + orig_lhs); if (w && is_gimple_min_invariant (w)) val.const_val = w; |