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| author | Andrew Pinski <quic_apinski@quicinc.com> | 2024-11-01 23:20:22 -0700 |
|---|---|---|
| committer | Andrew Pinski <quic_apinski@quicinc.com> | 2024-11-07 08:24:52 -0800 |
| commit | 684e5ae90b64c3481f8a5cb7b9517daf79c78ab4 (patch) | |
| tree | 472a345e1bd5095e4c3e262be42253c3cd67ab06 | |
| parent | add4bb94459d6cecae11de279b49f9c1acb14394 (diff) | |
| download | gcc-684e5ae90b64c3481f8a5cb7b9517daf79c78ab4.zip gcc-684e5ae90b64c3481f8a5cb7b9517daf79c78ab4.tar.gz gcc-684e5ae90b64c3481f8a5cb7b9517daf79c78ab4.tar.bz2 | |
VN: Lookup `val != 0` if we got back val when looking up the predicate for GIMPLE_COND [PR117414]
Sometimes we get back a full ssa name when looking up the comparison of the GIMPLE_COND
rather than a predicate. We then want to lookup the `val != 0` for the predicate.
Note this might happen with other boolean assignments and COND_EXPR but I am not sure
if it is as important; I have not found a testcase yet.
Bootstrapped and tested on x86_64-linux-gnu.
PR tree-optimization/117414
gcc/ChangeLog:
* tree-ssa-sccvn.cc (process_bb): Lookup
`val != 0` if got back a ssa name when looking the comparison.
gcc/testsuite/ChangeLog:
* gcc.dg/tree-ssa/fre-predicated-4.c: New test.
Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/fre-predicated-4.c | 38 | ||||
| -rw-r--r-- | gcc/tree-ssa-sccvn.cc | 10 |
2 files changed, 48 insertions, 0 deletions
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/fre-predicated-4.c b/gcc/testsuite/gcc.dg/tree-ssa/fre-predicated-4.c new file mode 100644 index 0000000..fe9d2e2 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/fre-predicated-4.c @@ -0,0 +1,38 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-optimized" } */ + +/* PR tree-optimization/117414 */ + +/* Fre1 should figure out that `*aaa != 0` + For f0 and f1. */ + + +void foo(); +int f0(int *aaa, int j, int t) +{ + int b = *aaa; + if (b == 0 || t == 1) + return 0; + for(int i = 0; i < j; i++) + { + if (!*aaa) foo(); + } + return 0; +} + +int f1(int *aaa, int j, int t) +{ + int b = *aaa; + if (b == 0) + return 0; + if (t == 1) + return 0; + for(int i = 0; i < j; i++) + { + if (!*aaa) foo(); + } + return 0; +} + +/* { dg-final { scan-tree-dump-not "foo " "optimized" } } */ +/* { dg-final { scan-tree-dump "return 0;" "optimized" } } */ diff --git a/gcc/tree-ssa-sccvn.cc b/gcc/tree-ssa-sccvn.cc index 67ed2cd..1967bbd 100644 --- a/gcc/tree-ssa-sccvn.cc +++ b/gcc/tree-ssa-sccvn.cc @@ -8159,6 +8159,16 @@ process_bb (rpo_elim &avail, basic_block bb, val = vn_nary_op_lookup_pieces (2, gimple_cond_code (last), boolean_type_node, ops, &vnresult); + /* Got back a ssa name, then try looking up `val != 0` + as it might have been recorded that way. */ + if (val && TREE_CODE (val) == SSA_NAME) + { + ops[0] = val; + ops[1] = build_zero_cst (TREE_TYPE (val)); + val = vn_nary_op_lookup_pieces (2, NE_EXPR, + boolean_type_node, ops, + &vnresult); + } /* Did we get a predicated value? */ if (! val && vnresult && vnresult->predicated_values) { |