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| author | Jan Hubicka <jh@suse.cz> | 2021-11-18 18:41:43 +0100 |
|---|---|---|
| committer | Jan Hubicka <jh@suse.cz> | 2021-11-18 18:41:43 +0100 |
| commit | c331a75d49b6043399f5ccce72a02ccf3b0ddc56 (patch) | |
| tree | 85a193a5b16480661b27e382ff7b0f54433c177a /gcc/ipa-modref.c | |
| parent | 4f0a2f5a3ddb1024b885c066a18caae4d733bb6c (diff) | |
| download | gcc-c331a75d49b6043399f5ccce72a02ccf3b0ddc56.zip gcc-c331a75d49b6043399f5ccce72a02ccf3b0ddc56.tar.gz gcc-c331a75d49b6043399f5ccce72a02ccf3b0ddc56.tar.bz2 | |
Fix modref wrt __builtin_assume_aligned
__builtin_assume_aligned has bit contraictionary fnspec description "1cX "
which means that parameter 1 is returned but also unused. PTA code takes
precedence to parameter being returned, while modref takes the info that
parameter is unused. This patch tweaks modref to follow PTA semantics (as
suggested by Richard in the PR log)
gcc/ChangeLog:
2021-11-18 Jan Hubicka <hubicka@ucw.cz>
PR ipa/103266
* ipa-modref.c (modref_eaf_analysis::merge_call_lhs_flags): Unused
parameter may still be returned.
(modref_eaf_analysis::analyze_ssa_name): Call merge_call_lhs_flags
even for unused function args.
gcc/testsuite/ChangeLog:
2021-11-18 Jan Hubicka <hubicka@ucw.cz>
PR ipa/103266
* g++.dg/torture/pr103266.C: New test.
Diffstat (limited to 'gcc/ipa-modref.c')
| -rw-r--r-- | gcc/ipa-modref.c | 32 |
1 files changed, 22 insertions, 10 deletions
diff --git a/gcc/ipa-modref.c b/gcc/ipa-modref.c index c94f058..e5d2b11 100644 --- a/gcc/ipa-modref.c +++ b/gcc/ipa-modref.c @@ -2033,10 +2033,7 @@ modref_eaf_analysis::merge_call_lhs_flags (gcall *call, int arg, bool indirect) { int index = SSA_NAME_VERSION (name); - - /* If value is not returned at all, do nothing. */ - if (!direct && !indirect) - return; + bool returned_directly = false; /* If there is no return value, no flags are affected. */ if (!gimple_call_lhs (call)) @@ -2047,10 +2044,23 @@ modref_eaf_analysis::merge_call_lhs_flags (gcall *call, int arg, if (arg >= 0) { int flags = gimple_call_return_flags (call); - if ((flags & ERF_RETURNS_ARG) - && (flags & ERF_RETURN_ARG_MASK) != arg) - return; + if (flags & ERF_RETURNS_ARG) + { + if ((flags & ERF_RETURN_ARG_MASK) == arg) + returned_directly = true; + else + return; + } + } + /* Make ERF_RETURNS_ARG overwrite EAF_UNUSED. */ + if (returned_directly) + { + direct = true; + indirect = false; } + /* If value is not returned at all, do nothing. */ + else if (!direct && !indirect) + return; /* If return value is SSA name determine its flags. */ if (TREE_CODE (gimple_call_lhs (call)) == SSA_NAME) @@ -2273,11 +2283,13 @@ modref_eaf_analysis::analyze_ssa_name (tree name) if (gimple_call_arg (call, i) == name) { int call_flags = gimple_call_arg_flags (call, i); - if (!ignore_retval && !(call_flags & EAF_UNUSED)) + if (!ignore_retval) merge_call_lhs_flags (call, i, name, - !(call_flags & EAF_NOT_RETURNED_DIRECTLY), - !(call_flags & EAF_NOT_RETURNED_INDIRECTLY)); + !(call_flags & (EAF_NOT_RETURNED_DIRECTLY + | EAF_UNUSED)), + !(call_flags & (EAF_NOT_RETURNED_INDIRECTLY + | EAF_UNUSED))); if (!(ecf_flags & (ECF_CONST | ECF_NOVOPS))) { call_flags = callee_to_caller_flags |