This patch updates to use the unordered comparison function for IEEE 128-bit
floating point to mimic the behaviour of SFmode/DFmode using the fcmpu
instruction.
It also restructures the code to allow a future change to drop in easier.
I have built the compiler with this patch and the previous subpatches (1-6). I
have bootstrapped the compiler with all 16 subpatches installed, and there were
no regressions. Is it ok to install in the trunk?
2015-10-22 Michael Meissner <meiss...@linux.vnet.ibm.com>
* config/rs6000/rs6000.c (rs6000_generate_compare): For IEEE
128-bit floating point comparisons, call the unordered comparison
function instead of the ordered comparison function.
(rs6000_expand_float128_convert): Deal with operands that are
memory operands. Restructure the code to use a switch statement on
the mode. Add support for TFmode defaulting to either IBM extended
double or IEEE 128-bit floating point. If the underlying types are
the same, use a move instead of a conversion function.
--
Michael Meissner, IBM
IBM, M/S 2506R, 550 King Street, Littleton, MA 01460-6245, USA
email: meiss...@linux.vnet.ibm.com, phone: +1 (978) 899-4797
Index: gcc/config/rs6000/rs6000.c
===================================================================
--- gcc/config/rs6000/rs6000.c (revision 229191)
+++ gcc/config/rs6000/rs6000.c (working copy)
@@ -20098,17 +20098,18 @@ rs6000_generate_compare (rtx cmp, machin
emit_insn (cmp);
}
- /* IEEE 128-bit support in VSX registers. The comparison function (__cmpkf2)
- returns 0..15 that is laid out the same way as the PowerPC CR register
- would for a normal floating point comparison. */
+ /* IEEE 128-bit support in VSX registers. The comparison functions
+ (__cmpokf2 and __cmpukf2) returns 0..15 that is laid out the same way as
+ the PowerPC CR register would for a normal floating point comparison from
+ the fcmpo and fcmpu instructions. */
else if (FLOAT128_IEEE_P (mode))
{
rtx and_reg = gen_reg_rtx (SImode);
rtx dest = gen_reg_rtx (SImode);
- rtx libfunc = optab_libfunc (cmp_optab, mode);
+ rtx libfunc = optab_libfunc (ucmp_optab, mode);
HOST_WIDE_INT mask_value = 0;
- /* Values that __cmpkf2 returns. */
+ /* Values that __cmpokf2/__cmpukf2 returns. */
#define PPC_CMP_UNORDERED 0x1 /* isnan (a) || isnan (b). */
#define PPC_CMP_EQUAL 0x2 /* a == b. */
#define PPC_CMP_GREATER_THEN 0x4 /* a > b. */
@@ -20280,6 +20281,7 @@ rs6000_generate_compare (rtx cmp, machin
}
+
/* Expand floating point conversion to/from __float128 and __ibm128. */
void
@@ -20288,60 +20290,121 @@ rs6000_expand_float128_convert (rtx dest
machine_mode dest_mode = GET_MODE (dest);
machine_mode src_mode = GET_MODE (src);
convert_optab cvt = unknown_optab;
+ bool do_move = false;
rtx libfunc = NULL_RTX;
rtx dest2;
if (dest_mode == src_mode)
gcc_unreachable ();
+ /* Eliminate memory operations. */
+ if (MEM_P (src))
+ src = force_reg (src_mode, src);
+
+ if (MEM_P (dest))
+ {
+ rtx tmp = gen_reg_rtx (dest_mode);
+ rs6000_expand_float128_convert (tmp, src, unsigned_p);
+ rs6000_emit_move (dest, tmp, dest_mode);
+ return;
+ }
+
+ /* Convert to IEEE 128-bit floating point. */
if (FLOAT128_IEEE_P (dest_mode))
{
- if (src_mode == SFmode
- || src_mode == DFmode
- || FLOAT128_IBM_P (src_mode))
- cvt = sext_optab;
+ switch (src_mode)
+ {
+ case DFmode:
+ cvt = sext_optab;
+ break;
- else if (GET_MODE_CLASS (src_mode) == MODE_INT)
- cvt = (unsigned_p) ? ufloat_optab : sfloat_optab;
+ case SFmode:
+ cvt = sext_optab;
+ break;
- else if (FLOAT128_IEEE_P (src_mode))
- emit_move_insn (dest, gen_lowpart (dest_mode, src));
+ case KFmode:
+ case IFmode:
+ case TFmode:
+ if (FLOAT128_IBM_P (src_mode))
+ cvt = sext_optab;
+ else
+ do_move = true;
+ break;
- else
- gcc_unreachable ();
+ case SImode:
+ case DImode:
+ cvt = (unsigned_p) ? ufloat_optab : sfloat_optab;
+ break;
+
+ default:
+ gcc_unreachable ();
+ }
}
+ /* Convert from IEEE 128-bit floating point. */
else if (FLOAT128_IEEE_P (src_mode))
{
- if (dest_mode == SFmode
- || dest_mode == DFmode
- || FLOAT128_IBM_P (dest_mode))
- cvt = trunc_optab;
+ switch (dest_mode)
+ {
+ case DFmode:
+ cvt = trunc_optab;
+ break;
- else if (GET_MODE_CLASS (dest_mode) == MODE_INT)
- cvt = (unsigned_p) ? ufix_optab : sfix_optab;
+ case SFmode:
+ cvt = trunc_optab;
+ break;
- else
- gcc_unreachable ();
+ case KFmode:
+ case IFmode:
+ case TFmode:
+ if (FLOAT128_IBM_P (dest_mode))
+ cvt = trunc_optab;
+ else
+ do_move = true;
+ break;
+
+ case SImode:
+ case DImode:
+ cvt = (unsigned_p) ? ufix_optab : sfix_optab;
+ break;
+
+ default:
+ gcc_unreachable ();
+ }
}
+ /* Both IBM format. */
+ else if (FLOAT128_IBM_P (dest_mode) && FLOAT128_IBM_P (src_mode))
+ do_move = true;
+
else
gcc_unreachable ();
- gcc_assert (cvt != unknown_optab);
- libfunc = convert_optab_libfunc (cvt, dest_mode, src_mode);
- gcc_assert (libfunc != NULL_RTX);
-
- dest2 = emit_library_call_value (libfunc, dest, LCT_CONST, dest_mode, 1, src,
- src_mode);
-
- gcc_assert (dest != NULL_RTX);
- if (!rtx_equal_p (dest, dest2))
- emit_move_insn (dest, dest2);
+ /* Handle conversion between TFmode/KFmode. */
+ if (do_move)
+ emit_move_insn (dest, gen_lowpart (dest_mode, src));
+
+ /* Call an external function to do the conversion. */
+ else if (cvt != unknown_optab)
+ {
+ libfunc = convert_optab_libfunc (cvt, dest_mode, src_mode);
+ gcc_assert (libfunc != NULL_RTX);
+
+ dest2 = emit_library_call_value (libfunc, dest, LCT_CONST, dest_mode, 1,
src,
+ src_mode);
+
+ gcc_assert (dest2 != NULL_RTX);
+ if (!rtx_equal_p (dest, dest2))
+ emit_move_insn (dest, dest2);
+ }
+
+ else
+ gcc_unreachable ();
return;
}
+
/* Emit the RTL for an sISEL pattern. */
void
