diff options
| author | Richard Henderson <rth@cygnus.com> | 1997-11-20 18:08:30 -0800 |
|---|---|---|
| committer | Jeff Law <law@gcc.gnu.org> | 1997-11-20 19:08:30 -0700 |
| commit | 858e4e8cfd71520171ec34839f62cae712b7ee55 (patch) | |
| tree | d4df3d888e247368c9d963fbbc6a0b0f90b9c83b /gcc | |
| parent | a21d14e9919cce73fd6aefed24054caebd175cae (diff) | |
| download | gcc-858e4e8cfd71520171ec34839f62cae712b7ee55.zip gcc-858e4e8cfd71520171ec34839f62cae712b7ee55.tar.gz gcc-858e4e8cfd71520171ec34839f62cae712b7ee55.tar.bz2 | |
* alpha.c (alpha_emit_set_const_1): Handle narrow hosts better.
From-SVN: r16627
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 4 | ||||
| -rw-r--r-- | gcc/config/alpha/alpha.c | 25 |
2 files changed, 22 insertions, 7 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 47734de..3771fac 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,7 @@ +Thu Nov 20 16:11:50 1997 Richard Henderson <rth@cygnus.com> + + * alpha.c (alpha_emit_set_const_1): Handle narrow hosts better. + Thu Nov 20 16:11:50 1997 Klaus Kaempf <kkaempf@progis.de> * alpha/vms.h (ASM_OUTPUT_ADDR_VEC_ELT): Add an L for the local label diff --git a/gcc/config/alpha/alpha.c b/gcc/config/alpha/alpha.c index ae119f3..6155a1d 100644 --- a/gcc/config/alpha/alpha.c +++ b/gcc/config/alpha/alpha.c @@ -904,12 +904,10 @@ alpha_emit_set_const_1 (target, mode, c, n) /* If this is a sign-extended 32-bit constant, we can do this in at most three insns, so do it if we have enough insns left. We always have - a sign-extended 32-bit constant when compiling on a narrow machine. - Note that we cannot handle the constant 0x80000000. */ + a sign-extended 32-bit constant when compiling on a narrow machine. */ - if ((HOST_BITS_PER_WIDE_INT != 64 - || c >> 31 == -1 || c >> 31 == 0) - && c != 0x80000000U) + if (HOST_BITS_PER_WIDE_INT != 64 + || c >> 31 == -1 || c >> 31 == 0) { HOST_WIDE_INT low = (c & 0xffff) - 2 * (c & 0x8000); HOST_WIDE_INT tmp1 = c - low; @@ -928,7 +926,18 @@ alpha_emit_set_const_1 (target, mode, c, n) } if (c == low || (low == 0 && extra == 0)) - return copy_to_suggested_reg (GEN_INT (c), target, mode); + { + /* We used to use copy_to_suggested_reg (GEN_INT (c), target, mode) + but that meant that we can't handle INT_MIN on 32-bit machines + (like NT/Alpha), because we recurse indefinitely through + emit_move_insn to gen_movdi. So instead, since we know exactly + what we want, create it explicitly. */ + + if (target == NULL) + target = gen_reg_rtx (mode); + emit_insn (gen_rtx (SET, VOIDmode, target, GEN_INT (c))); + return target; + } else if (n >= 2 + (extra != 0)) { temp = copy_to_suggested_reg (GEN_INT (low), subtarget, mode); @@ -1006,9 +1015,11 @@ alpha_emit_set_const_1 (target, mode, c, n) /* Now try high-order zero bits. Here we try the shifted-in bits as all zero and all ones. Be careful to avoid shifting outside the mode and to avoid shifting outside the host wide int size. */ + /* On narrow hosts, don't shift a 1 into the high bit, since we'll + confuse the recursive call and set all of the high 32 bits. */ if ((bits = (MIN (HOST_BITS_PER_WIDE_INT, GET_MODE_SIZE (mode) * 8) - - floor_log2 (c) - 1)) > 0) + - floor_log2 (c) - 1 - (HOST_BITS_PER_WIDE_INT < 64))) > 0) for (; bits > 0; bits--) if ((temp = alpha_emit_set_const (subtarget, mode, c << bits, i)) != 0 |