(gen_shl_and, gen_shl_sext): use gen_lowpart to generate rtx in the appropriate mode...

(gen_shl_and, gen_shl_sext): use gen_lowpart to
generate rtx in the appropriate mode for zero/sign-extension.
Don't generate a zero bit shift.
(gen_shl_sext) directly use gen_ashift instead of gen_ashrsi3 .

From-SVN: r12884

diff --git a/gcc/config/sh/sh.c b/gcc/config/sh/sh.c
index 490b202d590fd7545a0ca19ef4de03fbd06bcf73..c7e34d87ee6e95af81c5ca32408eb59ed6d51698 100644 (file)
--- a/gcc/config/sh/sh.c
+++ b/gcc/config/sh/sh.c
@@ -1232,10 +1232,10 @@ gen_shl_and (dest, left_rtx, mask_rtx, source)
        if (first < 0)
          {
            emit_insn ((mask << right) == 0xff
-                      ? gen_zero_extendqisi2(dest, gen_rtx (SUBREG, QImode,
-                                                            source, 0))
-                      : gen_zero_extendhisi2(dest, gen_rtx (SUBREG, HImode,
-                                                            source, 0)));
+                      ? gen_zero_extendqisi2(dest,
+                                             gen_lowpart (QImode, source))
+                      : gen_zero_extendhisi2(dest,
+                                             gen_lowpart (HImode, source)));
            source = dest;
          }
        if (source != dest)
@@ -1255,10 +1255,8 @@ gen_shl_and (dest, left_rtx, mask_rtx, source)
          }
        if (first >= 0)
          emit_insn (mask == 0xff
-                    ? gen_zero_extendqisi2(dest, gen_rtx (SUBREG, QImode,
-                                                          dest, 0))
-                    : gen_zero_extendhisi2(dest, gen_rtx (SUBREG, HImode,
-                                                          dest, 0)));
+                    ? gen_zero_extendqisi2(dest, gen_lowpart (QImode, dest))
+                    : gen_zero_extendhisi2(dest, gen_lowpart (HImode, dest)));
        if (total_shift > 0)
          {
            operands[2] = GEN_INT (total_shift);
@@ -1283,10 +1281,13 @@ gen_shl_and (dest, left_rtx, mask_rtx, source)
              source = dest;
            }
          emit_insn (gen_andsi3 (dest, source, GEN_INT (mask)));
-         operands[0] = dest;
-         operands[1] = dest;
-         operands[2] = GEN_INT (total_shift);
-         shift_gen_fun (ASHIFT, operands);
+         if (total_shift)
+           {
+             operands[0] = dest;
+             operands[1] = dest;
+             operands[2] = GEN_INT (total_shift);
+             shift_gen_fun (ASHIFT, operands);
+           }
          break;
        }
       else
@@ -1351,6 +1352,8 @@ shl_sext_kind (left_rtx, size_rtx, costp)
     {
       /* 16 bit shift / sign extend / 16 bit shift */
       cost = shift_insns[16 - insize] + 1 + ashiftrt_insns[16 - size];
+      /* If ashiftrt_insns[16 - size] is 8, this choice will be overridden
+        below, by alternative 3 or something even better.  */
       if (cost < best_cost)
        {
          kind = 5;
@@ -1470,41 +1473,50 @@ gen_shl_sext (dest, left_rtx, size_rtx, source)
        if (dest != source)
          emit_insn (gen_movsi (dest, source));
        operands[0] = dest;
-       operands[2] = GEN_INT (ext - insize);
-       gen_shifty_hi_op (ASHIFT, operands);
+       if (ext - insize)
+         {
+           operands[2] = GEN_INT (ext - insize);
+           gen_shifty_hi_op (ASHIFT, operands);
+         }
        emit_insn (kind & 1
-                  ? gen_extendqisi2(dest, gen_rtx (SUBREG, QImode, dest, 0))
-                  : gen_extendhisi2(dest, gen_rtx (SUBREG, HImode, dest, 0)));
+                  ? gen_extendqisi2(dest, gen_lowpart (QImode, dest))
+                  : gen_extendhisi2(dest, gen_lowpart (HImode, dest)));
        if (kind <= 2)
          {
-           operands[2] = GEN_INT (shift2);
-           gen_shifty_op (ASHIFT, operands);
+           if (shift2)
+             {
+               operands[2] = GEN_INT (shift2);
+               gen_shifty_op (ASHIFT, operands);
+             }
          }
        else
          {
-           if (shift2 >= 0)
+           if (shift2 > 0)
              {
                operands[2] = GEN_INT (shift2);
                gen_shifty_hi_op (ASHIFT, operands);
              }
-           else
+           else if (shift2)
              {
                operands[2] = GEN_INT (-shift2);
                gen_shifty_hi_op (LSHIFTRT, operands);
              }
            emit_insn (size <= 8
-                      ? gen_extendqisi2 (dest,
-                                         gen_rtx (SUBREG, QImode, dest, 0))
-                      : gen_extendhisi2 (dest,
-                                         gen_rtx (SUBREG, HImode, dest, 0)));
+                      ? gen_extendqisi2 (dest, gen_lowpart (QImode, dest))
+                      : gen_extendhisi2 (dest, gen_lowpart (HImode, dest)));
          }
        break;
       }
     case 5:
-      emit_insn (gen_shl_sext_ext (dest, source, GEN_INT (16 - insize),
-                                  GEN_INT (16)));
-      emit_insn (gen_ashrsi3 (dest, dest, GEN_INT (16 - size)));
-      break;
+      {
+       int i = 16 - size;
+       emit_insn (gen_shl_sext_ext (dest, source, GEN_INT (16 - insize),
+                                    GEN_INT (16)));
+       /* Don't use gen_ashrsi3 because it generates new pseudos.  */
+       while (--i >= 0)
+         gen_ashift (ASHIFTRT, 1, dest);
+       break;
+      }
     case 6:
     case 7:
       /* Don't expand fine-grained when combining, because that will