| Message ID | 20130812144622.09f848eb.yizhouzhou@ict.ac.cn |
|---|---|
| State | New |
| Headers | show |
On 08/12/2013 12:46 AM, Zhouyi Zhou wrote: > > In function get_default_value of tree-ssa-ccp.c, > 261 else if (is_gimple_assign (stmt) > 262 /* Value-returning GIMPLE_CALL statements assign to > 263 a variable, and are treated similarly to GIMPLE_ASSIGN. */ > 264 || (is_gimple_call (stmt) > 265 && gimple_call_lhs (stmt) != NULL_TREE) > 266 || gimple_code (stmt) == GIMPLE_PHI) > 267 { > 268 tree cst; > 269 if (gimple_assign_single_p (stmt) > 270 && DECL_P (gimple_assign_rhs1 (stmt)) > 271 && (cst = get_symbol_constant_value (gimple_assign_rhs1 (stmt)))) > 272 { > 273 val.lattice_val = CONSTANT; > 274 val.value = cst; > 275 } > 276 else > 277 /* Any other variable defined by an assignment or a PHI node > 278 is considered UNDEFINED. */ > 279 val.lattice_val = UNDEFINED; > if the stmt is a gimple call node or a gimple phi node, it will never satisfy > the condition gimple_assign_single_p (stmt). so there exists redundant condition > checks. The patch attached try to remove this. > > > Bootstrap passed. Regression tested on x86_64-unknown-linux-gnu (pc). > > ChangeLog: > 2013-08-13 Zhouyi Zhou <yizhouzhou@ict.ac.cn> > * tree-ssa-ccp.c (get_default_value): remove redundant condition checks Thanks. I fixed some minor formatting issues and committed your change after another bootstrap & regression test. Jeff
diff --git a/gcc/tree-ssa-ccp.c b/gcc/tree-ssa-ccp.c index 6472f48..7fbb687 100644 --- a/gcc/tree-ssa-ccp.c +++ b/gcc/tree-ssa-ccp.c @@ -258,12 +258,7 @@ get_default_value (tree var) val.mask = double_int_minus_one; } } - else if (is_gimple_assign (stmt) - /* Value-returning GIMPLE_CALL statements assign to - a variable, and are treated similarly to GIMPLE_ASSIGN. */ - || (is_gimple_call (stmt) - && gimple_call_lhs (stmt) != NULL_TREE) - || gimple_code (stmt) == GIMPLE_PHI) + else if (is_gimple_assign (stmt)) { tree cst; if (gimple_assign_single_p (stmt) @@ -274,10 +269,18 @@ get_default_value (tree var) val.value = cst; } else - /* Any other variable defined by an assignment or a PHI node + /* Any other variable defined by an assignment is considered UNDEFINED. */ val.lattice_val = UNDEFINED; } + else if ((is_gimple_call (stmt) + && gimple_call_lhs (stmt) != NULL_TREE) + || gimple_code (stmt) == GIMPLE_PHI) + { + /*Variable defined by a call or a PHI node + is considered UNDEFINED. */ + val.lattice_val = UNDEFINED; + } else { /* Otherwise, VAR will never take on a constant value. */
In function get_default_value of tree-ssa-ccp.c, 261 else if (is_gimple_assign (stmt) 262 /* Value-returning GIMPLE_CALL statements assign to 263 a variable, and are treated similarly to GIMPLE_ASSIGN. */ 264 || (is_gimple_call (stmt) 265 && gimple_call_lhs (stmt) != NULL_TREE) 266 || gimple_code (stmt) == GIMPLE_PHI) 267 { 268 tree cst; 269 if (gimple_assign_single_p (stmt) 270 && DECL_P (gimple_assign_rhs1 (stmt)) 271 && (cst = get_symbol_constant_value (gimple_assign_rhs1 (stmt)))) 272 { 273 val.lattice_val = CONSTANT; 274 val.value = cst; 275 } 276 else 277 /* Any other variable defined by an assignment or a PHI node 278 is considered UNDEFINED. */ 279 val.lattice_val = UNDEFINED; if the stmt is a gimple call node or a gimple phi node, it will never satisfy the condition gimple_assign_single_p (stmt). so there exists redundant condition checks. The patch attached try to remove this. Bootstrap passed. Regression tested on x86_64-unknown-linux-gnu (pc). ChangeLog: 2013-08-13 Zhouyi Zhou <yizhouzhou@ict.ac.cn> * tree-ssa-ccp.c (get_default_value): remove redundant condition checks