Hi!
If target (the real part thereof) overlap op1 (i.e. the imag part of
COMPLEX_EXPR
to be stored), we end up with first overwriting the real part and then
using wrong value in op1.
Fixed by testing for overlap, and either, if possible, doing the writes
in different order if overlap is detected (first write imag part, then real
part), or, if not possible, forcing op1 into a register.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2013-01-17 Jakub Jelinek <ja...@redhat.com>
PR middle-end/56015
* expr.c (expand_expr_real_2) <case COMPLEX_EXPR>: Handle
the case where writing real complex part of target modifies
op1.
* gfortran.dg/pr56015.f90: New test.
--- gcc/expr.c.jj 2013-01-11 09:02:48.000000000 +0100
+++ gcc/expr.c 2013-01-17 11:21:34.326854116 +0100
@@ -8860,6 +8860,54 @@ expand_expr_real_2 (sepops ops, rtx targ
if (!target)
target = gen_reg_rtx (TYPE_MODE (type));
+ else
+ /* If target overlaps with op1, then either we need to force
+ op1 into a pseudo (if target also overlaps with op0),
+ or write the complex parts in reverse order. */
+ switch (GET_CODE (target))
+ {
+ case CONCAT:
+ if (reg_overlap_mentioned_p (XEXP (target, 0), op1))
+ {
+ if (reg_overlap_mentioned_p (XEXP (target, 1), op0))
+ {
+ complex_expr_force_op1:
+ temp = gen_reg_rtx (GET_MODE_INNER (GET_MODE (target)));
+ emit_move_insn (temp, op1);
+ op1 = temp;
+ break;
+ }
+ complex_expr_swap_order:
+ /* Move the imaginary (op1) and real (op0) parts to their
+ location. */
+ write_complex_part (target, op1, true);
+ write_complex_part (target, op0, false);
+
+ return target;
+ }
+ break;
+ case MEM:
+ temp = adjust_address_nv (target,
+ GET_MODE_INNER (GET_MODE (target)), 0);
+ if (reg_overlap_mentioned_p (temp, op1))
+ {
+ enum machine_mode imode = GET_MODE_INNER (GET_MODE (target));
+ temp = adjust_address_nv (target, imode,
+ GET_MODE_SIZE (imode));
+ if (reg_overlap_mentioned_p (temp, op0))
+ goto complex_expr_force_op1;
+ goto complex_expr_swap_order;
+ }
+ break;
+ default:
+ if (reg_overlap_mentioned_p (target, op1))
+ {
+ if (reg_overlap_mentioned_p (target, op0))
+ goto complex_expr_force_op1;
+ goto complex_expr_swap_order;
+ }
+ break;
+ }
/* Move the real (op0) and imaginary (op1) parts to their location. */
write_complex_part (target, op0, false);
--- gcc/testsuite/gfortran.dg/pr56015.f90.jj 2013-01-17 11:16:27.793639775
+0100
+++ gcc/testsuite/gfortran.dg/pr56015.f90 2013-01-17 11:15:59.000000000
+0100
@@ -0,0 +1,16 @@
+! PR middle-end/56015
+! { dg-do run }
+! { dg-options "-Ofast -fno-inline" }
+
+program pr56015
+ implicit none
+ complex*16 p(10)
+ p(:) = (0.1d0, 0.2d0)
+ p(:) = (0.0d0, 1.0d0) * p(:)
+ call foo (p)
+contains
+ subroutine foo (p)
+ complex*16 p(10)
+ if (any (p .ne. (-0.2d0, 0.1d0))) call abort
+ end subroutine
+end program pr56015
Jakub
