Add copy_rtx call to RTL loop unroller

This is needed if the step is an unshared constant, like many
(const ...)s are.  Without this patch, libgfortran would fail
to build for SVE.

2017-09-21  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

gcc/
	* loop-unroll.c (split_iv): Call copy_rtx on the step.

Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>
From-SVN: r253058

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index a8d78c7ad58aeda897e17efe01c851281bdc2b55..7eec76768dd886a7deb6dabcffee46d33fbe55df 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2017-09-21  Richard Sandiford  <richard.sandiford@linaro.org>
+           Alan Hayward  <alan.hayward@arm.com>
+           David Sherwood  <david.sherwood@arm.com>
+
+       * loop-unroll.c (split_iv): Call copy_rtx on the step.
+
 2017-09-21  Richard Sandiford  <richard.sandiford@linaro.org>
            Alan Hayward  <alan.hayward@arm.com>
            David Sherwood  <david.sherwood@arm.com>

diff --git a/gcc/loop-unroll.c b/gcc/loop-unroll.c
index 8cf305b24c59aa27a0db4c39cbeaa6e98795c8f9..322f151ac5dfdc4f0303ee73ad8220fc694f30e8 100644 (file)
--- a/gcc/loop-unroll.c
+++ b/gcc/loop-unroll.c
@@ -1731,7 +1731,8 @@ split_iv (struct iv_to_split *ivts, rtx_insn *insn, unsigned delta)
   else
     {
       incr = simplify_gen_binary (MULT, mode,
-                                 ivts->step, gen_int_mode (delta, mode));
+                                 copy_rtx (ivts->step),
+                                 gen_int_mode (delta, mode));
       expr = simplify_gen_binary (PLUS, GET_MODE (ivts->base_var),
                                  ivts->base_var, incr);
     }