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| author | Roger Sayle <roger@nextmovesoftware.com> | 2020-07-13 09:49:34 +0100 |
|---|---|---|
| committer | Roger Sayle <roger@nextmovesoftware.com> | 2020-07-13 09:49:34 +0100 |
| commit | b8697d0cd06da3375063295fe7161671e0904459 (patch) | |
| tree | 2f0cef4cf9cb0bcd555a34db38e759d880e75825 /gcc/convert.c | |
| parent | 9a2ae08b02d185a11e3e525e100ba637ce81c7ff (diff) | |
| download | gcc-b8697d0cd06da3375063295fe7161671e0904459.zip gcc-b8697d0cd06da3375063295fe7161671e0904459.tar.gz gcc-b8697d0cd06da3375063295fe7161671e0904459.tar.bz2 | |
middle-end: Remove truly_noop_truncation check from convert.c
This patch eliminates a check of targetm.truly_noop_truncation from
the early middle-end, where the gimple/generic being generated by
GCC's front-ends is being inappropriately influenced by the target's
TRULY_NOOP_TRUNCATION. The (recent) intention of TRULY_NOOP_TRUNCATION
is to indicate that a backend requires explicit truncation instructions
rather than using SUBREGs to perform truncations. A long standing
(and probably unintentional) side-effect has been that this setting
also controls whether the middle-end narrows integer operations at
the tree-level. Understandably, GCC and its testsuite assume that
GIMPLE and GENERIC behave consistently across platforms, and alas
defining TRULY_NOOP_TRUNCATION away from the default triggers several
regressions (including gcc.dg/fold-rotate-1.c).
2020-07-13 Roger Sayle <roger@nextmovesoftware.com>
gcc/ChangeLog
* convert.c (convert_to_integer_1): Narrow integer operations
even on targets that require explicit truncation instructions.
Diffstat (limited to 'gcc/convert.c')
| -rw-r--r-- | gcc/convert.c | 14 |
1 files changed, 4 insertions, 10 deletions
diff --git a/gcc/convert.c b/gcc/convert.c index 42509c5..292c513 100644 --- a/gcc/convert.c +++ b/gcc/convert.c @@ -836,16 +836,10 @@ convert_to_integer_1 (tree type, tree expr, bool dofold) && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (arg1, 0)))) break; - if (outprec >= BITS_PER_WORD - || targetm.truly_noop_truncation (outprec, inprec) - || inprec > TYPE_PRECISION (TREE_TYPE (arg0)) - || inprec > TYPE_PRECISION (TREE_TYPE (arg1))) - { - tree tem = do_narrow (loc, ex_form, type, arg0, arg1, - expr, inprec, outprec, dofold); - if (tem) - return tem; - } + tree tem = do_narrow (loc, ex_form, type, arg0, arg1, + expr, inprec, outprec, dofold); + if (tem) + return tem; } break; |