re PR rtl-optimization/64286 (Redundant extend removal ignores vector element type)

	PR rtl-optimization/64286
	* ree.c (combine_reaching_defs): Move part of comment earlier,
	remove !SCALAR_INT_MODE_P check.
	(add_removable_extension): Don't add vector mode
	extensions if all uses of the source register aren't the same
	vector extensions.

	* gcc.target/i386/avx2-pr64286.c: New test.

From-SVN: r219550

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index b8886d260a38416731341fa5c67ef6ea79a708e8..725d7a6ca67d0824c9cdf529f4ac27020c29c117 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+2015-01-13  Jakub Jelinek  <jakub@redhat.com>
+
+       PR rtl-optimization/64286
+       * ree.c (combine_reaching_defs): Move part of comment earlier,
+       remove !SCALAR_INT_MODE_P check.
+       (add_removable_extension): Don't add vector mode
+       extensions if all uses of the source register aren't the same
+       vector extensions.
+
 2015-01-13  Renlin Li  <renlin.li@arm.com>
 
        * config/arm/arm.h (CLZ_DEFINED_VALUE_AT_ZERO): Return 2.

diff --git a/gcc/ree.c b/gcc/ree.c
index bf872a25386f82ba9b0feb4b2ffba4584dd4fe60..2fea2c880cf7aa6133f04a0b487ed6cf414f2dba 100644 (file)
--- a/gcc/ree.c
+++ b/gcc/ree.c
@@ -783,6 +783,17 @@ combine_reaching_defs (ext_cand *cand, const_rtx set_pat, ext_state *state)
        != REGNO (get_extended_src_reg (SET_SRC (PATTERN (cand->insn)))));
   if (copy_needed)
     {
+      /* Considering transformation of
+        (set (reg1) (expression))
+        ...
+        (set (reg2) (any_extend (reg1)))
+
+        into
+
+        (set (reg2) (any_extend (expression)))
+        (set (reg1) (reg2))
+        ...  */
+
       /* In theory we could handle more than one reaching def, it
         just makes the code to update the insn stream more complex.  */
       if (state->defs_list.length () != 1)
@@ -798,18 +809,6 @@ combine_reaching_defs (ext_cand *cand, const_rtx set_pat, ext_state *state)
       if (state->modified[INSN_UID (cand->insn)].kind != EXT_MODIFIED_NONE)
        return false;
 
-      /* Transformation of
-        (set (reg1) (expression))
-        (set (reg2) (any_extend (reg1)))
-        into
-        (set (reg2) (any_extend (expression)))
-        (set (reg1) (reg2))
-        is only valid for scalar integral modes, as it relies on the low
-        subreg of reg1 to have the value of (expression), which is not true
-        e.g. for vector modes.  */
-      if (!SCALAR_INT_MODE_P (GET_MODE (SET_DEST (PATTERN (cand->insn)))))
-       return false;
-
       machine_mode dst_mode = GET_MODE (SET_DEST (PATTERN (cand->insn)));
       rtx src_reg = get_extended_src_reg (SET_SRC (PATTERN (cand->insn)));
 
@@ -1027,6 +1026,7 @@ add_removable_extension (const_rtx expr, rtx_insn *insn,
         different extension.  FIXME: this obviously can be improved.  */
       for (def = defs; def; def = def->next)
        if ((idx = def_map[INSN_UID (DF_REF_INSN (def->ref))])
+           && idx != -1U
            && (cand = &(*insn_list)[idx - 1])
            && cand->code != code)
          {
@@ -1038,6 +1038,57 @@ add_removable_extension (const_rtx expr, rtx_insn *insn,
              }
            return;
          }
+       /* For vector mode extensions, ensure that all uses of the
+          XEXP (src, 0) register are the same extension (both code
+          and to which mode), as unlike integral extensions lowpart
+          subreg of the sign/zero extended register are not equal
+          to the original register, so we have to change all uses or
+          none.  */
+       else if (VECTOR_MODE_P (GET_MODE (XEXP (src, 0))))
+         {
+           if (idx == 0)
+             {
+               struct df_link *ref_chain, *ref_link;
+
+               ref_chain = DF_REF_CHAIN (def->ref);
+               for (ref_link = ref_chain; ref_link; ref_link = ref_link->next)
+                 {
+                   if (ref_link->ref == NULL
+                       || DF_REF_INSN_INFO (ref_link->ref) == NULL)
+                     {
+                       idx = -1U;
+                       break;
+                     }
+                   rtx_insn *use_insn = DF_REF_INSN (ref_link->ref);
+                   const_rtx use_set;
+                   if (use_insn == insn || DEBUG_INSN_P (use_insn))
+                     continue;
+                   if (!(use_set = single_set (use_insn))
+                       || !REG_P (SET_DEST (use_set))
+                       || GET_MODE (SET_DEST (use_set)) != GET_MODE (dest)
+                       || GET_CODE (SET_SRC (use_set)) != code
+                       || !rtx_equal_p (XEXP (SET_SRC (use_set), 0),
+                                        XEXP (src, 0)))
+                     {
+                       idx = -1U;
+                       break;
+                     }
+                 }
+               if (idx == -1U)
+                 def_map[INSN_UID (DF_REF_INSN (def->ref))] = idx;
+             }
+           if (idx == -1U)
+             {
+               if (dump_file)
+                 {
+                   fprintf (dump_file, "Cannot eliminate extension:\n");
+                   print_rtl_single (dump_file, insn);
+                   fprintf (dump_file,
+                            " because some vector uses aren't extension\n");
+                 }
+               return;
+             }
+         }
 
       /* Then add the candidate to the list and insert the reaching definitions
          into the definition map.  */

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 5a09e16cb8cfd6357df4fef9500b9f8a8b80ef13..3263f13c58dd4d02fd7a661e27a7017c10b9fac3 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2015-01-13  Jakub Jelinek  <jakub@redhat.com>
+
+       PR rtl-optimization/64286
+       * gcc.target/i386/avx2-pr64286.c: New test.
+
 2015-01-13  Paolo Carlini  <paolo.carlini@oracle.com>
 
        PR c++/57626

diff --git a/gcc/testsuite/gcc.target/i386/avx2-pr64286.c b/gcc/testsuite/gcc.target/i386/avx2-pr64286.c
new file mode 100644 (file)
index 0000000..2edb321
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/avx2-pr64286.c
@@ -0,0 +1,37 @@
+/* PR rtl-optimization/64286 */
+/* { dg-do run } */
+/* { dg-options "-O2 -mavx2" } */
+/* { dg-require-effective-target avx2 } */
+
+#include <string.h>
+#include <stdlib.h>
+#include <x86intrin.h>
+#include "avx2-check.h"
+
+__m128i v;
+__m256i w;
+
+__attribute__((noinline, noclone)) void
+foo (__m128i *p, __m128i *q)
+{
+  __m128i a = _mm_loadu_si128 (p);
+  __m128i b = _mm_xor_si128 (a, v);
+  w = _mm256_cvtepu8_epi16 (a);
+  *q = b;
+}
+
+static void
+avx2_test (void)
+{
+  v = _mm_set1_epi8 (0x40);
+  __m128i c = _mm_set_epi8 (16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1);
+  __m128i d;
+  foo (&c, &d);
+  __m128i e = _mm_set_epi8 (0x50, 0x4f, 0x4e, 0x4d, 0x4c, 0x4b, 0x4a, 0x49,
+                           0x48, 0x47, 0x46, 0x45, 0x44, 0x43, 0x42, 0x41);
+  __m256i f = _mm256_set_epi16 (16, 15, 14, 13, 12, 11, 10, 9,
+                               8, 7, 6, 5, 4, 3, 2, 1);
+  if (memcmp (&w, &f, sizeof (w)) != 0
+      || memcmp (&d, &e, sizeof (d)) != 0)
+    abort ();
+}