Hello!
v2 of the patch hits the real problem: in pass_expand::execute
finish_eh_generation is called after expand_stack_alignment is called.
Construction of SjLj landing pads calls emit_library_call, which can
change crtl->preferred_stack_boundary value after all dependant
variables are already calculated by expand_stack_alignment.
The solution is to move the call to finish_eh_generation in front of
the call to expand_stack_alignment.
2018-11-01 Uros Bizjak <ubiz...@gmail.com>
PR middle-end/58372
* cfgexpand.c (pass_expand::execute): Move the call to
finish_eh_generation in front of the call to expand_stack_alignment.
testsuite/ChangeLog:
2018-11-01 Uros Bizjak <ubiz...@gmail.com>
PR middle-end/58372
* g++.target/i386/pr58372.C: New test.
Patch was bootstrapped and regression tested on x86_64-linux-gnu
{,-m32}, all default languages plus go. Additionally, the testcase
from PR (and a couple of similar ones) were compiled for
i686-w64-mingw32 target with various combinations of
-mpreferred-stack-boundary= -mincoming-stack-boundary= -mforce-drap
and -m{no-}accumulate-outgoing-args.
OK for mainline and release branches?
Uros.
Index: cfgexpand.c
===================================================================
--- cfgexpand.c (revision 265582)
+++ cfgexpand.c (working copy)
@@ -6510,6 +6510,12 @@ pass_expand::execute (function *fun)
find_many_sub_basic_blocks (blocks);
purge_all_dead_edges ();
+ /* After initial rtl generation, call back to finish generating
+ exception support code. We need to do this before cleaning up
+ the CFG as the code does not expect dead landing pads. */
+ if (fun->eh->region_tree != NULL)
+ finish_eh_generation ();
+
expand_stack_alignment ();
/* Fixup REG_EQUIV notes in the prologue if there are tailcalls in this
@@ -6517,12 +6523,6 @@ pass_expand::execute (function *fun)
if (crtl->tail_call_emit)
fixup_tail_calls ();
- /* After initial rtl generation, call back to finish generating
- exception support code. We need to do this before cleaning up
- the CFG as the code does not expect dead landing pads. */
- if (fun->eh->region_tree != NULL)
- finish_eh_generation ();
-
/* BB subdivision may have created basic blocks that are are only reachable
from unlikely bbs but not marked as such in the profile. */
if (optimize)
Index: testsuite/g++.target/i386/pr58372.C
===================================================================
--- testsuite/g++.target/i386/pr58372.C (nonexistent)
+++ testsuite/g++.target/i386/pr58372.C (working copy)
@@ -0,0 +1,9 @@
+/* PR target/58372 */
+/* { dg-do compile { target c++14 } } */
+/* { dg-options "-O2" } */
+
+__attribute__ ((__target__ ("rdrnd")))
+void f (unsigned int *b) noexcept
+{
+ __builtin_ia32_rdrand32_step (b);
+}
