On Wed, Dec 4, 2013 at 12:56 PM, Richard Sandiford
<rdsandif...@googlemail.com> wrote:
> Richard Sandiford <rdsandif...@googlemail.com> writes:
>> This patch handles multiplications using a single HWIxHWI->2HWI
>> multiplication
>> on hosts that have one. This removes all uses of the slow (half-HWI) path
>> for insn-recog.ii. The slow path is still used 58 times for cp/parser.ii
>> and 168 times for fold-const.ii, but at that kind of level it shouldn't
>> matter much.
>>
>> I followed Joseph's suggestion and reused longlong.h. I copied it from
>> libgcc rather than glibc since it seemed better for GCC to have a single
>> version across both gcc/ and libgcc/. I can put it in include/ if that
>> seems better.
>
> I've committed the patch to move longlong.h to trunk and merged back
> to the branch, so all that's left is the wide-int.cc patch. OK to install?
>
> Thanks,
> Richard
>
>
> Index: gcc/wide-int.cc
> ===================================================================
> --- gcc/wide-int.cc 2013-12-03 23:59:08.133658567 +0000
> +++ gcc/wide-int.cc 2013-12-04 12:55:28.466895358 +0000
> @@ -27,6 +27,16 @@ along with GCC; see the file COPYING3.
> #include "tree.h"
> #include "dumpfile.h"
>
> +#if GCC_VERSION >= 3000
> +#define W_TYPE_SIZE HOST_BITS_PER_WIDE_INT
> +typedef unsigned HOST_HALF_WIDE_INT UHWtype;
> +typedef unsigned HOST_WIDE_INT UWtype;
> +typedef unsigned int UQItype __attribute__ ((mode (QI)));
> +typedef unsigned int USItype __attribute__ ((mode (SI)));
> +typedef unsigned int UDItype __attribute__ ((mode (DI)));
> +#include "longlong.h"
We also need something like the attached patch to handle architectures
which use UDWType in longlong.h. I noticed this when trying rth's
patch stack http://gcc.gnu.org/ml/gcc-patches/2014-01/msg00391.html to
improve longlong.h for AArch64.
It's needed when rth's patches go in finally for aarch64 but could
probably go in now - after all the comment in longlong.h says you need
to define UDWtype ... Don't mind either way.
regards
Ramana
<DATE> Ramana Radhakrishnan <ramana.radhakrish...@arm.com>
* wide-int.cc (UTItype): Define.
(UDWtype): Define for appropriate W_TYPE_SIZE.
> +#endif
> +
> /* This is the maximal size of the buffer needed for dump. */
> const unsigned int MAX_SIZE = (4 * (MAX_BITSIZE_MODE_ANY_INT / 4
> + (MAX_BITSIZE_MODE_ANY_INT
> @@ -1255,8 +1265,8 @@ wi_pack (unsigned HOST_WIDE_INT *result,
> record in *OVERFLOW whether the result overflowed. SGN controls
> the signedness and is used to check overflow or if HIGH is set. */
> unsigned int
> -wi::mul_internal (HOST_WIDE_INT *val, const HOST_WIDE_INT *op1,
> - unsigned int op1len, const HOST_WIDE_INT *op2,
> +wi::mul_internal (HOST_WIDE_INT *val, const HOST_WIDE_INT *op1val,
> + unsigned int op1len, const HOST_WIDE_INT *op2val,
> unsigned int op2len, unsigned int prec, signop sgn,
> bool *overflow, bool high)
> {
> @@ -1285,24 +1295,53 @@ wi::mul_internal (HOST_WIDE_INT *val, co
> if (needs_overflow)
> *overflow = false;
>
> + wide_int_ref op1 = wi::storage_ref (op1val, op1len, prec);
> + wide_int_ref op2 = wi::storage_ref (op2val, op2len, prec);
> +
> /* This is a surprisingly common case, so do it first. */
> - if ((op1len == 1 && op1[0] == 0) || (op2len == 1 && op2[0] == 0))
> + if (op1 == 0 || op2 == 0)
> {
> val[0] = 0;
> return 1;
> }
>
> +#ifdef umul_ppmm
> + if (sgn == UNSIGNED)
> + {
> + /* If the inputs are single HWIs and the output has room for at
> + least two HWIs, we can use umul_ppmm directly. */
> + if (prec >= HOST_BITS_PER_WIDE_INT * 2
> + && wi::fits_uhwi_p (op1)
> + && wi::fits_uhwi_p (op2))
> + {
> + umul_ppmm (val[1], val[0], op1.ulow (), op2.ulow ());
> + return 1 + (val[1] != 0 || val[0] < 0);
> + }
> + /* Likewise if the output is a full single HWI, except that the
> + upper HWI of the result is only used for determining overflow.
> + (We handle this case inline when overflow isn't needed.) */
> + else if (prec == HOST_BITS_PER_WIDE_INT)
> + {
> + unsigned HOST_WIDE_INT upper;
> + umul_ppmm (upper, val[0], op1.ulow (), op2.ulow ());
> + if (needs_overflow)
> + *overflow = (upper != 0);
> + return 1;
> + }
> + }
> +#endif
> +
> /* Handle multiplications by 1. */
> - if (op1len == 1 && op1[0] == 1)
> + if (op1 == 1)
> {
> for (i = 0; i < op2len; i++)
> - val[i] = op2[i];
> + val[i] = op2val[i];
> return op2len;
> }
> - if (op2len == 1 && op2[0] == 1)
> + if (op2 == 1)
> {
> for (i = 0; i < op1len; i++)
> - val[i] = op1[i];
> + val[i] = op1val[i];
> return op1len;
> }
>
> @@ -1316,13 +1355,13 @@ wi::mul_internal (HOST_WIDE_INT *val, co
>
> if (sgn == SIGNED)
> {
> - o0 = sext_hwi (op1[0], prec);
> - o1 = sext_hwi (op2[0], prec);
> + o0 = op1.to_shwi ();
> + o1 = op2.to_shwi ();
> }
> else
> {
> - o0 = zext_hwi (op1[0], prec);
> - o1 = zext_hwi (op2[0], prec);
> + o0 = op1.to_uhwi ();
> + o1 = op2.to_uhwi ();
> }
>
> r = o0 * o1;
> @@ -1344,9 +1383,9 @@ wi::mul_internal (HOST_WIDE_INT *val, co
> }
>
> /* We do unsigned mul and then correct it. */
> - wi_unpack (u, (const unsigned HOST_WIDE_INT*)op1, op1len,
> + wi_unpack (u, (const unsigned HOST_WIDE_INT *) op1val, op1len,
> half_blocks_needed, prec, SIGNED);
> - wi_unpack (v, (const unsigned HOST_WIDE_INT*)op2, op2len,
> + wi_unpack (v, (const unsigned HOST_WIDE_INT *) op2val, op2len,
> half_blocks_needed, prec, SIGNED);
>
> /* The 2 is for a full mult. */
> @@ -1371,7 +1410,7 @@ wi::mul_internal (HOST_WIDE_INT *val, co
> if (sgn == SIGNED && (high || needs_overflow))
> {
> unsigned HOST_WIDE_INT b;
> - if (op1[op1len-1] < 0)
> + if (wi::neg_p (op1))
> {
> b = 0;
> for (i = 0; i < half_blocks_needed; i++)
> @@ -1382,7 +1421,7 @@ wi::mul_internal (HOST_WIDE_INT *val, co
> b = t >> (HOST_BITS_PER_WIDE_INT - 1);
> }
> }
> - if (op2[op2len-1] < 0)
> + if (wi::neg_p (op2))
> {
> b = 0;
> for (i = 0; i < half_blocks_needed; i++)
commit 62672d152281515c1d97ec1370698544cb2c81b6
Author: Ramana Radhakrishnan <ramana.radhakrish...@arm.com>
Date: Thu May 8 09:56:59 2014 +0000
Fix up UDWtype for wide-int merge.
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 354cdb9..8ef9a0f 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2014-05-08 Ramana Radhakrishnan <ramana.radhakrish...@arm.com>
+
+ * wide-int.cc (UTItype): Define.
+ (UDWtype): Define for appropriate W_TYPE_SIZE.
+
2014-05-08 Alan Modra <amo...@gmail.com>
PR target/60737
diff --git a/gcc/wide-int.cc b/gcc/wide-int.cc
index 69a15bc..3552e03 100644
--- a/gcc/wide-int.cc
+++ b/gcc/wide-int.cc
@@ -34,6 +34,12 @@ typedef unsigned HOST_WIDE_INT UWtype;
typedef unsigned int UQItype __attribute__ ((mode (QI)));
typedef unsigned int USItype __attribute__ ((mode (SI)));
typedef unsigned int UDItype __attribute__ ((mode (DI)));
+typedef unsigned int UTItype __attribute__ ((mode (TI)));
+#if W_TYPE_SIZE == 32
+# define UDWtype UDItype
+#elif W_TYPE_SIZE == 64
+# define UDWtype UTItype
+#endif
#include "longlong.h"
#endif
