My fixing of store-sinking exposed an issue that relying on SSA
update to fixup virtual operands isn't a good idea if we incrementally
walk through all sinking candidates. Fixed by manually updating virtual
SSA form which is easy in this case.
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.
Richard.
2011-03-16 Richard Guenther <rguent...@suse.de>
PR tree-optimization/48146
* tree-ssa-sink.c (sink_code_in_bb): Manually update virtual
operands avoiding the need for renaming.
* gcc.dg/torture/pr48146.c: New testcase.
Index: gcc/tree-ssa-sink.c
===================================================================
*** gcc/tree-ssa-sink.c (revision 171039)
--- gcc/tree-ssa-sink.c (working copy)
*************** sink_code_in_bb (basic_block bb)
*** 505,516 ****
bb->index, (gsi_bb (togsi))->index);
}
! /* Prepare for VOP update. */
if (gimple_vdef (stmt))
{
! unlink_stmt_vdef (stmt);
! gimple_set_vdef (stmt, gimple_vop (cfun));
! mark_sym_for_renaming (gimple_vop (cfun));
}
/* If this is the end of the basic block, we need to insert at the end
--- 505,522 ----
bb->index, (gsi_bb (togsi))->index);
}
! /* Update virtual operands of statements in the path we
! do not sink to. */
if (gimple_vdef (stmt))
{
! imm_use_iterator iter;
! use_operand_p use_p;
! gimple vuse_stmt;
!
! FOR_EACH_IMM_USE_STMT (vuse_stmt, iter, gimple_vdef (stmt))
! if (gimple_code (vuse_stmt) != GIMPLE_PHI)
! FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
! SET_USE (use_p, gimple_vuse (stmt));
}
/* If this is the end of the basic block, we need to insert at the end
Index: gcc/testsuite/gcc.dg/torture/pr48146.c
===================================================================
*** gcc/testsuite/gcc.dg/torture/pr48146.c (revision 0)
--- gcc/testsuite/gcc.dg/torture/pr48146.c (revision 0)
***************
*** 0 ****
--- 1,35 ----
+ /* { dg-do compile } */
+
+ static unsigned char
+ safe_sub_func_int_s_s (int si1, unsigned char si2)
+ {
+ return si1 ^ si2 & -si2 ^ si2 ? : si1 - si2;
+ }
+
+ int g_2[10] = {
+ 0x90AC204EL
+ };
+
+ volatile unsigned char g_39;
+
+ unsigned char
+ func_67 (unsigned short p_68)
+ {
+ unsigned char l_92;
+ unsigned char l_74;
+ int *l = &g_2[6];
+ lbl_90:*l ^= 1;
+ if (p_68)
+ goto lbl_93;
+ for (l_74 = 0;; l_74 = safe_sub_func_int_s_s (l_74, 1))
+ {
+ if (l_74)
+ goto lbl_90;
+ lbl_93:l_92 ^= 0 != &g_39;
+ if (0)
+ {
+ }
+ else
+ *l = 1;
+ }
+ }
