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| author | Ilya Leoshkevich <iii@linux.ibm.com> | 2019-10-07 14:59:00 +0000 |
|---|---|---|
| committer | Ilya Leoshkevich <iii@gcc.gnu.org> | 2019-10-07 14:59:00 +0000 |
| commit | 70e2a30ac8f474feefbcc392cbc59cf91271b92b (patch) | |
| tree | 3302596f71ab0b28e68060f10d0b68451d44590c /gcc/tree-eh.c | |
| parent | 880dcdaedac453d2c64ebcc6f1bb5f81539c863c (diff) | |
| download | gcc-70e2a30ac8f474feefbcc392cbc59cf91271b92b.zip gcc-70e2a30ac8f474feefbcc392cbc59cf91271b92b.tar.gz gcc-70e2a30ac8f474feefbcc392cbc59cf91271b92b.tar.bz2 | |
Allow COND_EXPR and VEC_COND_EXPR condtions to trap
Right now gimplifier does not allow VEC_COND_EXPR's condition to trap
and introduces a temporary if this could happen, for example, generating
_5 = _4 > { 2.0e+0, 2.0e+0, 2.0e+0, 2.0e+0 };
_6 = VEC_COND_EXPR <_5, { -1, -1, -1, -1 }, { 0, 0, 0, 0 }>;
from GENERIC
VEC_COND_EXPR < (*b > { 2.0e+0, 2.0e+0, 2.0e+0, 2.0e+0 }) ,
{ -1, -1, -1, -1 } ,
{ 0, 0, 0, 0 } >
This is not necessary and makes the resulting GIMPLE harder to analyze.
Change the gimplifier so as to allow COND_EXPR and VEC_COND_EXPR
conditions to trap.
This patch takes special care to avoid introducing trapping comparisons
in GIMPLE_COND. They are not allowed, because they would require 3
outgoing edges (then, else and EH), which is awkward to say the least.
Therefore, computations of such conditions should live in their own basic
blocks.
gcc/ChangeLog:
2019-10-07 Ilya Leoshkevich <iii@linux.ibm.com>
PR target/77918
* gimple-expr.c (gimple_cond_get_ops_from_tree): Assert that the
caller passes a non-trapping condition.
(is_gimple_condexpr): Allow trapping conditions.
(is_gimple_condexpr_1): New helper function.
(is_gimple_condexpr_for_cond): New function, acts like old
is_gimple_condexpr.
* gimple-expr.h (is_gimple_condexpr_for_cond): New function.
* gimple.c (gimple_could_trap_p_1): Handle COND_EXPR and
VEC_COND_EXPR. Fix an issue with statements like i = (fp < 1.).
* gimplify.c (gimplify_cond_expr): Use
is_gimple_condexpr_for_cond.
(gimplify_expr): Allow is_gimple_condexpr_for_cond.
* tree-eh.c (operation_could_trap_p): Assert on COND_EXPR and
VEC_COND_EXPR.
(tree_could_trap_p): Handle COND_EXPR and VEC_COND_EXPR.
* tree-ssa-forwprop.c (forward_propagate_into_gimple_cond): Use
is_gimple_condexpr_for_cond, remove pointless tmp check
(forward_propagate_into_cond): Remove pointless tmp check.
From-SVN: r276659
Diffstat (limited to 'gcc/tree-eh.c')
| -rw-r--r-- | gcc/tree-eh.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/gcc/tree-eh.c b/gcc/tree-eh.c index 1aba733..7a02873 100644 --- a/gcc/tree-eh.c +++ b/gcc/tree-eh.c @@ -2523,6 +2523,10 @@ operation_could_trap_p (enum tree_code op, bool fp_operation, bool honor_trapv, bool honor_snans = fp_operation && flag_signaling_nans != 0; bool handled; + /* This function cannot tell whether or not COND_EXPR and VEC_COND_EXPR could + trap, because that depends on the respective condition op. */ + gcc_assert (op != COND_EXPR && op != VEC_COND_EXPR); + if (TREE_CODE_CLASS (op) != tcc_comparison && TREE_CODE_CLASS (op) != tcc_unary && TREE_CODE_CLASS (op) != tcc_binary) @@ -2610,6 +2614,10 @@ tree_could_trap_p (tree expr) if (!expr) return false; + /* For COND_EXPR and VEC_COND_EXPR only the condition may trap. */ + if (TREE_CODE (expr) == COND_EXPR || TREE_CODE (expr) == VEC_COND_EXPR) + expr = TREE_OPERAND (expr, 0); + code = TREE_CODE (expr); t = TREE_TYPE (expr); |