[AArch64][5/5] Cleanup immediate generation code in aarch64_internal_mov_immediate

2015-09-20  Wilco Dijkstra  <wdijkstr@arm.com>

	* config/aarch64/aarch64.c (aarch64_internal_mov_immediate): Cleanup
	immediate generation code.

From-SVN: r227950

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index befa118..9a76fc4 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,10 @@
 2015-09-20  Wilco Dijkstra  <wdijkstr@arm.com>
 
+       * config/aarch64/aarch64.c (aarch64_internal_mov_immediate): Cleanup
+       immediate generation code.
+
+2015-09-20  Wilco Dijkstra  <wdijkstr@arm.com>
+
        * config/aarch64/aarch64.c (aarch64_internal_mov_immediate): Remove
        redundant immediate generation code.
 

diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index af8ec3c..39ed15e 100644 (file)
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -1433,75 +1433,42 @@ static int
 aarch64_internal_mov_immediate (rtx dest, rtx imm, bool generate,
                                machine_mode mode)
 {
-  unsigned HOST_WIDE_INT mask;
   int i;
-  bool first;
-  unsigned HOST_WIDE_INT val, val2;
-  int one_match, zero_match, first_not_ffff_match;
-  int num_insns = 0;
+  unsigned HOST_WIDE_INT val, val2, mask;
+  int one_match, zero_match;
+  int num_insns;
 
-  if (CONST_INT_P (imm) && aarch64_move_imm (INTVAL (imm), mode))
+  val = INTVAL (imm);
+
+  if (aarch64_move_imm (val, mode))
     {
       if (generate)
        emit_insn (gen_rtx_SET (dest, imm));
-      num_insns++;
-      return num_insns;
+      return 1;
     }
 
-  if (mode == SImode)
+  if ((val >> 32) == 0 || mode == SImode)
     {
-      /* We know we can't do this in 1 insn, and we must be able to do it
-        in two; so don't mess around looking for sequences that don't buy
-        us anything.  */
       if (generate)
        {
-         emit_insn (gen_rtx_SET (dest, GEN_INT (INTVAL (imm) & 0xffff)));
-         emit_insn (gen_insv_immsi (dest, GEN_INT (16),
-                                    GEN_INT ((INTVAL (imm) >> 16) & 0xffff)));
+         emit_insn (gen_rtx_SET (dest, GEN_INT (val & 0xffff)));
+         if (mode == SImode)
+           emit_insn (gen_insv_immsi (dest, GEN_INT (16),
+                                      GEN_INT ((val >> 16) & 0xffff)));
+         else
+           emit_insn (gen_insv_immdi (dest, GEN_INT (16),
+                                      GEN_INT ((val >> 16) & 0xffff)));
        }
-      num_insns += 2;
-      return num_insns;
+      return 2;
     }
 
   /* Remaining cases are all for DImode.  */
 
-  val = INTVAL (imm);
-
-  one_match = 0;
-  zero_match = 0;
   mask = 0xffff;
-  first_not_ffff_match = -1;
-
-  for (i = 0; i < 64; i += 16, mask <<= 16)
-    {
-      if ((val & mask) == mask)
-       one_match++;
-      else
-       {
-         if (first_not_ffff_match < 0)
-           first_not_ffff_match = i;
-         if ((val & mask) == 0)
-           zero_match++;
-       }
-    }
-
-  if (one_match == 2)
-    {
-      /* Set one of the quarters and then insert back into result.  */
-      mask = 0xffffll << first_not_ffff_match;
-      if (generate)
-       {
-         emit_insn (gen_rtx_SET (dest, GEN_INT (val | mask)));
-         emit_insn (gen_insv_immdi (dest, GEN_INT (first_not_ffff_match),
-                                    GEN_INT ((val >> first_not_ffff_match)
-                                             & 0xffff)));
-       }
-      num_insns += 2;
-      return num_insns;
-    }
-
-  if (zero_match == 2)
-    goto simple_sequence;
+  zero_match = ((val & mask) == 0) + ((val & (mask << 16)) == 0) +
+    ((val & (mask << 32)) == 0) + ((val & (mask << 48)) == 0);
+  one_match = ((~val & mask) == 0) + ((~val & (mask << 16)) == 0) +
+    ((~val & (mask << 32)) == 0) + ((~val & (mask << 48)) == 0);
 
   if (zero_match != 2 && one_match != 2)
     {
@@ -1529,58 +1496,32 @@ aarch64_internal_mov_immediate (rtx dest, rtx imm, bool generate,
            {
              emit_insn (gen_rtx_SET (dest, GEN_INT (val2)));
              emit_insn (gen_insv_immdi (dest, GEN_INT (i),
-                        GEN_INT ((val >> i) & 0xffff)));
+                                        GEN_INT ((val >> i) & 0xffff)));
            }
-         return 2;
        }
     }
 
-  if (one_match > zero_match)
-    {
-      /* Set either first three quarters or all but the third.  */
-      mask = 0xffffll << (16 - first_not_ffff_match);
-      if (generate)
-       emit_insn (gen_rtx_SET (dest,
-                               GEN_INT (val | mask | 0xffffffff00000000ull)));
-      num_insns ++;
+  /* Generate 2-4 instructions, skipping 16 bits of all zeroes or ones which
+     are emitted by the initial mov.  If one_match > zero_match, skip set bits,
+     otherwise skip zero bits.  */
 
-      /* Now insert other two quarters.         */
-      for (i = first_not_ffff_match + 16, mask <<= (first_not_ffff_match << 1);
-          i < 64; i += 16, mask <<= 16)
-       {
-         if ((val & mask) != mask)
-           {
-             if (generate)
-               emit_insn (gen_insv_immdi (dest, GEN_INT (i),
-                                          GEN_INT ((val >> i) & 0xffff)));
-             num_insns ++;
-           }
-       }
-      return num_insns;
-    }
-
- simple_sequence:
-  first = true;
+  num_insns = 1;
   mask = 0xffff;
-  for (i = 0; i < 64; i += 16, mask <<= 16)
+  val2 = one_match > zero_match ? ~val : val;
+  i = (val2 & mask) != 0 ? 0 : (val2 & (mask << 16)) != 0 ? 16 : 32;
+
+  if (generate)
+    emit_insn (gen_rtx_SET (dest, GEN_INT (one_match > zero_match
+                                          ? (val | ~(mask << i))
+                                          : (val & (mask << i)))));
+  for (i += 16; i < 64; i += 16)
     {
-      if ((val & mask) != 0)
-       {
-         if (first)
-           {
-             if (generate)
-               emit_insn (gen_rtx_SET (dest, GEN_INT (val & mask)));
-             num_insns ++;
-             first = false;
-           }
-         else
-           {
-             if (generate)
-               emit_insn (gen_insv_immdi (dest, GEN_INT (i),
-                                          GEN_INT ((val >> i) & 0xffff)));
-             num_insns ++;
-           }
-       }
+      if ((val2 & (mask << i)) == 0)
+       continue;
+      if (generate)
+       emit_insn (gen_insv_immdi (dest, GEN_INT (i),
+                                  GEN_INT ((val >> i) & 0xffff)));
+      num_insns ++;
     }
 
   return num_insns;