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Backported patch to 4.7 branch
- From: Jakub Jelinek <jakub at redhat dot com>
- To: gcc-patches at gcc dot gnu dot org
- Date: Mon, 13 Aug 2012 09:37:12 +0200
- Subject: Backported patch to 4.7 branch
- Reply-to: Jakub Jelinek <jakub at redhat dot com>
Hi!
I've bootstrapped/regtested on x86_64-linux and i686-linux and committed the
following backport to 4.7 branch.
2012-08-13 Jakub Jelinek <jakub@redhat.com>
Backported from trunk
2012-07-19 Jakub Jelinek <jakub@redhat.com>
PR rtl-optimization/53942
* function.c (assign_parm_setup_reg): Avoid zero/sign extension
directly from likely spilled non-fixed hard registers, move them
to pseudo first.
* gcc.dg/pr53942.c: New test.
--- gcc/function.c (revision 189680)
+++ gcc/function.c (revision 189681)
@@ -2987,11 +2987,26 @@ assign_parm_setup_reg (struct assign_par
&& insn_operand_matches (icode, 1, op1))
{
enum rtx_code code = unsignedp ? ZERO_EXTEND : SIGN_EXTEND;
- rtx insn, insns;
+ rtx insn, insns, t = op1;
HARD_REG_SET hardregs;
start_sequence ();
- insn = gen_extend_insn (op0, op1, promoted_nominal_mode,
+ /* If op1 is a hard register that is likely spilled, first
+ force it into a pseudo, otherwise combiner might extend
+ its lifetime too much. */
+ if (GET_CODE (t) == SUBREG)
+ t = SUBREG_REG (t);
+ if (REG_P (t)
+ && HARD_REGISTER_P (t)
+ && ! TEST_HARD_REG_BIT (fixed_reg_set, REGNO (t))
+ && targetm.class_likely_spilled_p (REGNO_REG_CLASS (REGNO (t))))
+ {
+ t = gen_reg_rtx (GET_MODE (op1));
+ emit_move_insn (t, op1);
+ }
+ else
+ t = op1;
+ insn = gen_extend_insn (op0, t, promoted_nominal_mode,
data->passed_mode, unsignedp);
emit_insn (insn);
insns = get_insns ();
--- gcc/testsuite/gcc.dg/pr53942.c (revision 0)
+++ gcc/testsuite/gcc.dg/pr53942.c (revision 189681)
@@ -0,0 +1,34 @@
+/* PR rtl-optimization/53942 */
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+/* { dg-additional-options "-mtune=pentium2" { target { { i?86-*-* x86_64-*-* } && ia32 } } } */
+
+struct S
+{
+ unsigned short w[3];
+ unsigned int x, y;
+};
+
+struct S *baz (void);
+
+__attribute__ ((noinline))
+static unsigned char
+foo (struct S *x, unsigned char y)
+{
+ unsigned char c = 0;
+ unsigned char v = x->w[0];
+ c |= v;
+ v = ((x->w[1]) & (1 << y)) ? 1 : 0;
+ c |= v << 1;
+ v = ((x->w[2]) & 0xff) & (1 << y);
+ c |= v << 2;
+ return c;
+}
+
+void
+bar (void)
+{
+ struct S *s = baz ();
+ s->x = foo (s, 6);
+ s->y = foo (s, 7);
+}
Jakub