On Sat, Feb 25, 2017 at 08:42:33AM +0100, Richard Biener wrote:
> On February 24, 2017 9:56:25 PM GMT+01:00, Jakub Jelinek <ja...@redhat.com>
> wrote:
> >Hi!
> >
> >On the following testcase we replace a PLUS_EXPR (which is considered
> >throwing with -fnon-call-exceptions when it has floating point
> >arguments
> >and FP exceptions or sNaNs are enabled) with a FMA_EXPR; I believe it
> >can throw the same, but stmt_could_throw_1_p doesn't think so (as it is
> >not unary/binary/comparison). While we could tweak the widen_mul patch
> >to deal with dropping EH from gsi_replace and cleaning up cfg etc., I
> >believe the right fix is to fix stmt_could_throw_1_p.
> >
> >Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
>
> OK. Can you make sure this is then consistent with the other throw
> predicates?.
may_trap_p_1 handles FMA right, no idea what other predicates could cover
that on RTL. But you're right, operation_could_trap_p used by
tree_could_trap_p needs the same treatment:
2017-02-25 Jakub Jelinek <ja...@redhat.com>
PR middle-end/79396
* tree-eh.c (operation_could_trap_p, stmt_could_throw_1_p): Handle
FMA_EXPR like tcc_binary or tcc_unary.
* g++.dg/opt/pr79396.C: New test.
--- gcc/tree-eh.c.jj 2017-02-24 21:39:01.240088691 +0100
+++ gcc/tree-eh.c 2017-02-25 09:21:06.017859379 +0100
@@ -2513,7 +2513,8 @@ operation_could_trap_p (enum tree_code o
if (TREE_CODE_CLASS (op) != tcc_comparison
&& TREE_CODE_CLASS (op) != tcc_unary
- && TREE_CODE_CLASS (op) != tcc_binary)
+ && TREE_CODE_CLASS (op) != tcc_binary
+ && op != FMA_EXPR)
return false;
return operation_could_trap_helper_p (op, fp_operation, honor_trapv,
@@ -2738,7 +2739,8 @@ stmt_could_throw_1_p (gimple *stmt)
if (TREE_CODE_CLASS (code) == tcc_comparison
|| TREE_CODE_CLASS (code) == tcc_unary
- || TREE_CODE_CLASS (code) == tcc_binary)
+ || TREE_CODE_CLASS (code) == tcc_binary
+ || code == FMA_EXPR)
{
if (is_gimple_assign (stmt)
&& TREE_CODE_CLASS (code) == tcc_comparison)
--- gcc/testsuite/g++.dg/opt/pr79396.C.jj 2017-02-25 09:20:03.608706718
+0100
+++ gcc/testsuite/g++.dg/opt/pr79396.C 2017-02-25 09:20:03.607706732 +0100
@@ -0,0 +1,13 @@
+// PR middle-end/79396
+// { dg-do compile }
+// { dg-options "-fnon-call-exceptions -O2" }
+// { dg-additional-options "-mfma" { target i?86-*-* x86_64-*-* } }
+
+struct A { A (); ~A (); };
+
+float
+foo (float x)
+{
+ A a;
+ return __builtin_pow (x, 2) + 2;
+}
Jakub
