projects / packages / gcc.git / blame
| Commit | Line | Data |
|---|---|---|
| 82a0d200 PS |
1 | Date: Tue, 6 Dec 2005 21:31:58 +0100 |
| 2 | From: Zdenek Dvorak <rakdver at atrey dot karlin dot mff dot cuni dot cz> | |
| 3 | Subject: [patch] for PR 25248 | |
| 4 | ||
| 5 | Hello, | |
| 6 | ||
| 7 | when follow_ssa_edge_in_rhs analyzes expression of form a + b, it first | |
| 8 | tries to analyze a, and if it fails, analyzes b. The results are | |
| 9 | accumulated to evolution_of_loop. However, the failed attempt to analyze 'a' may | |
| 10 | modify contents of evolution_of_loop; the result of analysis of 'b' is | |
| 11 | then combined with it, which produces a wrong result. Fixed by using a | |
| 12 | temporary variable to store the result in the analysis of 'a'. | |
| 13 | ||
| 14 | Bootstrapped & regtested on i686 and ppc64. | |
| 15 | ||
| 16 | Zdenek | |
| 17 | ||
| 18 | PR tree-optimization/25248 | |
| 19 | * tree-scalar-evolution.c (follow_ssa_edge_in_rhs): Do not use | |
| 20 | evolution_of_loop from the failed attempt. | |
| 21 | ||
| 22 | Index: tree-scalar-evolution.c | |
| 23 | =================================================================== | |
| 24 | *** gcc/gcc/tree-scalar-evolution.c (revision 108078) | |
| 25 | --- gcc/gcc/tree-scalar-evolution.c (working copy) | |
| 26 | *************** follow_ssa_edge_in_rhs (struct loop *loo | |
| 27 | *** 1042,1047 **** | |
| 28 | --- 1042,1048 ---- | |
| 29 | t_bool res = t_false; | |
| 30 | tree rhs0, rhs1; | |
| 31 | tree type_rhs = TREE_TYPE (rhs); | |
| 32 | + tree evol; | |
| 33 | ||
| 34 | /* The RHS is one of the following cases: | |
| 35 | - an SSA_NAME, | |
| 36 | *************** follow_ssa_edge_in_rhs (struct loop *loo | |
| 37 | *** 1084,1097 **** | |
| 38 | { | |
| 39 | /* Match an assignment under the form: | |
| 40 | "a = b + c". */ | |
| 41 | res = follow_ssa_edge | |
| 42 | (loop, SSA_NAME_DEF_STMT (rhs0), halting_phi, | |
| 43 | ! evolution_of_loop, limit); | |
| 44 | ||
| 45 | if (res == t_true) | |
| 46 | *evolution_of_loop = add_to_evolution | |
| 47 | (loop->num, | |
| 48 | ! chrec_convert (type_rhs, *evolution_of_loop, at_stmt), | |
| 49 | PLUS_EXPR, rhs1); | |
| 50 | ||
| 51 | else if (res == t_false) | |
| 52 | --- 1085,1099 ---- | |
| 53 | { | |
| 54 | /* Match an assignment under the form: | |
| 55 | "a = b + c". */ | |
| 56 | + evol = *evolution_of_loop; | |
| 57 | res = follow_ssa_edge | |
| 58 | (loop, SSA_NAME_DEF_STMT (rhs0), halting_phi, | |
| 59 | ! &evol, limit); | |
| 60 | ||
| 61 | if (res == t_true) | |
| 62 | *evolution_of_loop = add_to_evolution | |
| 63 | (loop->num, | |
| 64 | ! chrec_convert (type_rhs, evol, at_stmt), | |
| 65 | PLUS_EXPR, rhs1); | |
| 66 | ||
| 67 | else if (res == t_false) |