* [PATCH] tree-optimization/100519 - avoid reassociating asm goto defs
@ 2021-05-12 11:12 Richard Biener
0 siblings, 0 replies; only message in thread
From: Richard Biener @ 2021-05-12 11:12 UTC (permalink / raw)
To: gcc-patches
This splits can_associate_p into checks for SSA defs and checks
for the type so it can be called from is_reassociable_op to
catch cases not catched by the earlier fix.
Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.
2021-05-11 Richard Biener <rguenther@suse.de>
PR tree-optimization/100519
* tree-ssa-reassoc.c (can_associate_p): Split into...
(can_associate_op_p): ... this
(can_associate_type_p): ... and this.
(is_reassociable_op): Call can_associate_op_p.
(break_up_subtract_bb): Call the appropriate predicates.
(reassociate_bb): Likewise.
* gcc.dg/torture/pr100519.c: New testcase.
---
gcc/testsuite/gcc.dg/torture/pr100519.c | 13 ++++
gcc/tree-ssa-reassoc.c | 86 +++++++++++++------------
2 files changed, 58 insertions(+), 41 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/torture/pr100519.c
diff --git a/gcc/testsuite/gcc.dg/torture/pr100519.c b/gcc/testsuite/gcc.dg/torture/pr100519.c
new file mode 100644
index 00000000000..faf6e240e08
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr100519.c
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-additional-options "--param tree-reassoc-width=2" } */
+
+unsigned int foo_a1, foo_a2;
+
+unsigned int foo()
+{
+ unsigned int v0, x;
+ asm goto("" : "=r"(x) : : : lab);
+lab:
+ v0 += x + x;
+ return v0 + x + foo_a1 + foo_a2;
+}
diff --git a/gcc/tree-ssa-reassoc.c b/gcc/tree-ssa-reassoc.c
index 359367c9382..32e1632705b 100644
--- a/gcc/tree-ssa-reassoc.c
+++ b/gcc/tree-ssa-reassoc.c
@@ -593,6 +593,36 @@ add_repeat_to_ops_vec (vec<operand_entry *> *ops, tree op,
reassociate_stats.pows_encountered++;
}
+/* Returns true if we can associate the SSA def OP. */
+
+static bool
+can_reassociate_op_p (tree op)
+{
+ if (TREE_CODE (op) == SSA_NAME && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (op))
+ return false;
+ /* Make sure asm goto outputs do not participate in reassociation since
+ we have no way to find an insertion place after asm goto. */
+ if (TREE_CODE (op) == SSA_NAME
+ && gimple_code (SSA_NAME_DEF_STMT (op)) == GIMPLE_ASM
+ && gimple_asm_nlabels (as_a <gasm *> (SSA_NAME_DEF_STMT (op))) != 0)
+ return false;
+ return true;
+}
+
+/* Returns true if we can reassociate operations of TYPE.
+ That is for integral or non-saturating fixed-point types, and for
+ floating point type when associative-math is enabled. */
+
+static bool
+can_reassociate_type_p (tree type)
+{
+ if ((ANY_INTEGRAL_TYPE_P (type) && TYPE_OVERFLOW_WRAPS (type))
+ || NON_SAT_FIXED_POINT_TYPE_P (type)
+ || (flag_associative_math && FLOAT_TYPE_P (type)))
+ return true;
+ return false;
+}
+
/* Return true if STMT is reassociable operation containing a binary
operation with tree code CODE, and is inside LOOP. */
@@ -613,12 +643,8 @@ is_reassociable_op (gimple *stmt, enum tree_code code, class loop *loop)
{
tree rhs1 = gimple_assign_rhs1 (stmt);
tree rhs2 = gimple_assign_rhs2 (stmt);
- if (TREE_CODE (rhs1) == SSA_NAME
- && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rhs1))
- return false;
- if (rhs2
- && TREE_CODE (rhs2) == SSA_NAME
- && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rhs2))
+ if (!can_reassociate_op_p (rhs1)
+ || (rhs2 && !can_reassociate_op_p (rhs2)))
return false;
return true;
}
@@ -5887,29 +5913,6 @@ repropagate_negates (void)
}
}
-/* Returns true if OP is of a type for which we can do reassociation.
- That is for integral or non-saturating fixed-point types, and for
- floating point type when associative-math is enabled. */
-
-static bool
-can_reassociate_p (tree op)
-{
- tree type = TREE_TYPE (op);
- if (TREE_CODE (op) == SSA_NAME && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (op))
- return false;
- /* Make sure asm goto outputs do not participate in reassociation since
- we have no way to find an insertion place after asm goto. */
- if (TREE_CODE (op) == SSA_NAME
- && gimple_code (SSA_NAME_DEF_STMT (op)) == GIMPLE_ASM
- && gimple_asm_nlabels (as_a <gasm *> (SSA_NAME_DEF_STMT (op))) != 0)
- return false;
- if ((ANY_INTEGRAL_TYPE_P (type) && TYPE_OVERFLOW_WRAPS (type))
- || NON_SAT_FIXED_POINT_TYPE_P (type)
- || (flag_associative_math && FLOAT_TYPE_P (type)))
- return true;
- return false;
-}
-
/* Break up subtract operations in block BB.
We do this top down because we don't know whether the subtract is
@@ -5942,14 +5945,15 @@ break_up_subtract_bb (basic_block bb)
gimple_set_uid (stmt, uid++);
if (!is_gimple_assign (stmt)
- || !can_reassociate_p (gimple_assign_lhs (stmt)))
+ || !can_reassociate_type_p (TREE_TYPE (gimple_assign_lhs (stmt)))
+ || !can_reassociate_op_p (gimple_assign_lhs (stmt)))
continue;
/* Look for simple gimple subtract operations. */
if (gimple_assign_rhs_code (stmt) == MINUS_EXPR)
{
- if (!can_reassociate_p (gimple_assign_rhs1 (stmt))
- || !can_reassociate_p (gimple_assign_rhs2 (stmt)))
+ if (!can_reassociate_op_p (gimple_assign_rhs1 (stmt))
+ || !can_reassociate_op_p (gimple_assign_rhs2 (stmt)))
continue;
/* Check for a subtract used only in an addition. If this
@@ -5960,7 +5964,7 @@ break_up_subtract_bb (basic_block bb)
break_up_subtract (stmt, &gsi);
}
else if (gimple_assign_rhs_code (stmt) == NEGATE_EXPR
- && can_reassociate_p (gimple_assign_rhs1 (stmt)))
+ && can_reassociate_op_p (gimple_assign_rhs1 (stmt)))
plus_negates.safe_push (gimple_assign_lhs (stmt));
}
for (son = first_dom_son (CDI_DOMINATORS, bb);
@@ -6553,14 +6557,14 @@ reassociate_bb (basic_block bb)
/* For non-bit or min/max operations we can't associate
all types. Verify that here. */
- if (rhs_code != BIT_IOR_EXPR
- && rhs_code != BIT_AND_EXPR
- && rhs_code != BIT_XOR_EXPR
- && rhs_code != MIN_EXPR
- && rhs_code != MAX_EXPR
- && (!can_reassociate_p (lhs)
- || !can_reassociate_p (rhs1)
- || !can_reassociate_p (rhs2)))
+ if ((rhs_code != BIT_IOR_EXPR
+ && rhs_code != BIT_AND_EXPR
+ && rhs_code != BIT_XOR_EXPR
+ && rhs_code != MIN_EXPR
+ && rhs_code != MAX_EXPR
+ && !can_reassociate_type_p (TREE_TYPE (lhs)))
+ || !can_reassociate_op_p (rhs1)
+ || !can_reassociate_op_p (rhs2))
continue;
if (associative_tree_code (rhs_code))
--
2.26.2
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