On 09/09/14 16:58, Xinliang David Li wrote:
> The attached patch fixed the problem reported in PR63209. The problem
> exists in both gcc4.9 and trunk.
>
> Regression test on arm-unknown-linux-gnueabi passes.
>
> Ok for gcc-4.9 and trunk?
>
No, this isn't right. I don't think you need a new pattern here (you
certainly don't want a new insn - at most you would just need a new
split). But I think you just need some special case code in the
existing pattern to handle the overlap case.
Also, please do not post ChangeLog entries in patch format; they won't
apply by the time the patch is ready to be committed.
R.
> (I sent the patch last night, but it got lost somehow)
>
>
> David
>
>
> pr63209.txt
>
>
> Index: ChangeLog
> ===================================================================
> --- ChangeLog (revision 215039)
> +++ ChangeLog (working copy)
> @@ -1,3 +1,9 @@
> +2014-09-08 Xinliang David Li <davi...@google.com>
> +
> + PR target/63209
> + * config/arm/arm.md (movcond_addsi_1): New pattern.
> + (movcond_addsi): Add a constraint.
> +
> 2014-09-08 Trevor Saunders <tsaund...@mozilla.com>
>
> * common/config/picochip/picochip-common.c: Remove.
> Index: config/arm/arm.md
> ===================================================================
> --- config/arm/arm.md (revision 215039)
> +++ config/arm/arm.md (working copy)
> @@ -9302,6 +9302,43 @@
> (set_attr "type" "multiple")]
> )
>
> +(define_insn_and_split "movcond_addsi_1"
> + [(set (match_operand:SI 0 "s_register_operand" "=r,l,r")
> + (if_then_else:SI
> + (match_operator 4 "comparison_operator"
> + [(plus:SI (match_operand:SI 2 "s_register_operand" "r,r,r")
> + (match_operand:SI 3 "arm_add_operand" "rIL,rIL,rIL"))
> + (const_int 0)])
> + (match_operand:SI 1 "arm_rhs_operand" "rI,rPy,r")
> + (match_dup:SI 0)))
> + (clobber (reg:CC CC_REGNUM))]
> + "TARGET_32BIT"
> + "#"
> + "&& reload_completed"
> + [(set (reg:CC_NOOV CC_REGNUM)
> + (compare:CC_NOOV
> + (plus:SI (match_dup 2)
> + (match_dup 3))
> + (const_int 0)))
> + (cond_exec (match_dup 5)
> + (set (match_dup 0) (match_dup 1)))]
> + "
> + {
> + enum machine_mode mode = SELECT_CC_MODE (GET_CODE (operands[4]),
> + operands[2], operands[3]);
> + enum rtx_code rc = GET_CODE (operands[4]);
> +
> + operands[5] = gen_rtx_REG (mode, CC_REGNUM);
> + gcc_assert (!(mode == CCFPmode || mode == CCFPEmode));
> + operands[5] = gen_rtx_fmt_ee (rc, VOIDmode, operands[5], const0_rtx);
> + }
> + "
> + [(set_attr "conds" "clob")
> + (set_attr "enabled_for_depr_it" "no,yes,yes")
> + (set_attr "type" "multiple")]
> +)
> +
> +
> (define_insn_and_split "movcond_addsi"
> [(set (match_operand:SI 0 "s_register_operand" "=r,l,r")
> (if_then_else:SI
> @@ -9312,7 +9349,7 @@
> (match_operand:SI 1 "arm_rhs_operand" "rI,rPy,r")
> (match_operand:SI 2 "arm_rhs_operand" "rI,rPy,r")))
> (clobber (reg:CC CC_REGNUM))]
> - "TARGET_32BIT"
> + "TARGET_32BIT && REGNO (operands[2]) != REGNO (operands[0])"
> "#"
> "&& reload_completed"
> [(set (reg:CC_NOOV CC_REGNUM)
> Index: testsuite/ChangeLog
> ===================================================================
> --- testsuite/ChangeLog (revision 215039)
> +++ testsuite/ChangeLog (working copy)
> @@ -1,3 +1,8 @@
> +2014-09-08 Xinliang David Li <davi...@google.com>
> +
> + PR target/63209
> + * gcc.c-torture/execute/pr63209.c: New test
> +
> 2014-09-08 Jakub Jelinek <ja...@redhat.com>
>
> PR tree-optimization/60196
> Index: testsuite/gcc.c-torture/execute/pr63209.c
> ===================================================================
> --- testsuite/gcc.c-torture/execute/pr63209.c (revision 0)
> +++ testsuite/gcc.c-torture/execute/pr63209.c (revision 0)
> @@ -0,0 +1,27 @@
> +static int Sub(int a, int b) {
> + return b -a;
> +}
> +
> +static unsigned Select(unsigned a, unsigned b, unsigned c) {
> + const int pa_minus_pb =
> + Sub((a >> 8) & 0xff, (b >> 8) & 0xff) +
> + Sub((a >> 0) & 0xff, (b >> 0) & 0xff);
> + return (pa_minus_pb <= 0) ? a : b;
> +}
> +
> +__attribute__((noinline)) unsigned Predictor(unsigned left, const unsigned*
> const top) {
> + const unsigned pred = Select(top[1], left, top[0]);
> + return pred;
> +}
> +
> +int main(void) {
> + const unsigned top[2] = {0xff7a7a7a, 0xff7a7a7a};
> + const unsigned left = 0xff7b7b7b;
> + const unsigned pred = Predictor(left, top /*+ 1*/);
> + if (pred == left)
> + return 0;
> + return 1;
> +}
> +
> +
> +
>
