https://gcc.gnu.org/g:8079e96eb767851e8e061a13ecfb21aa1a2362de
commit r16-3176-g8079e96eb767851e8e061a13ecfb21aa1a2362de
Author: Yang Yujie <yangyu...@loongson.cn>
Date: Sat Aug 2 17:16:23 2025 +0800
LoongArch: Add support for _BitInt [PR117599]
This patch adds support for C23's _BitInt for LoongArch.
From the LoongArch psABI[1]:
> _BitInt(N) objects are stored in little-endian order in memory
> and are signed by default.
>
> For N ≤ 64, a _BitInt(N) object have the same size and alignment
> of the smallest fundamental integral type that can contain it.
> The unused high-order bits within this containing type are filled
> with sign or zero extension of the N-bit value, depending on whether
> the _BitInt(N) object is signed or unsigned. The _BitInt(N) object
> propagates its signedness to the containing type and is laid out
> in a register or memory as an object of this type.
>
> For N > 64, _BitInt(N) objects are implemented as structs of 64-bit
> integer chunks. The number of chunks is the smallest even integer M
> so that M * 64 ≥ N. These objects are of the same size of the struct
> containing the chunks, but always have 16-byte alignment. If there
> are unused bits in the highest-ordered chunk that contains used
> bits, they are defined as the sign- or zero- extension of the used
> bits depending on whether the _BitInt(N) object is signed or
> unsigned. If an entire chunk is unused, its bits are undefined.
[1] https://github.com/loongson/la-abi-specs
PR target/117599
gcc/ChangeLog:
* config/loongarch/loongarch.h: Define a PROMOTE_MODE case for
small _BitInts.
* config/loongarch/loongarch.cc (loongarch_promote_function_mode):
Same.
(loongarch_bitint_type_info): New function.
(TARGET_C_BITINT_TYPE_INFO): Declare.
libgcc/ChangeLog:
* config/loongarch/t-softfp-tf: Enable _BitInt helper functions.
* config/loongarch/t-loongarch: Same.
* config/loongarch/libgcc-loongarch.ver: New file.
gcc/testsuite/ChangeLog:
* gcc.target/loongarch/bitint-alignments.c: New test.
* gcc.target/loongarch/bitint-args.c: New test.
* gcc.target/loongarch/bitint-sizes.c: New test.
Diff:
---
gcc/config/loongarch/loongarch.cc | 35 +++++++++-
gcc/config/loongarch/loongarch.h | 4 +-
.../gcc.target/loongarch/bitint-alignments.c | 58 ++++++++++++++++
gcc/testsuite/gcc.target/loongarch/bitint-args.c | 81 ++++++++++++++++++++++
gcc/testsuite/gcc.target/loongarch/bitint-sizes.c | 60 ++++++++++++++++
libgcc/config/loongarch/libgcc-loongarch.ver | 28 ++++++++
libgcc/config/loongarch/t-loongarch | 2 +
libgcc/config/loongarch/t-softfp-tf | 1 +
8 files changed, 266 insertions(+), 3 deletions(-)
diff --git a/gcc/config/loongarch/loongarch.cc
b/gcc/config/loongarch/loongarch.cc
index 493f95e16191..b169d2ffcd06 100644
--- a/gcc/config/loongarch/loongarch.cc
+++ b/gcc/config/loongarch/loongarch.cc
@@ -10786,9 +10786,9 @@ loongarch_expand_vec_cmp (rtx operands[])
to a fixed type. */
static machine_mode
-loongarch_promote_function_mode (const_tree type ATTRIBUTE_UNUSED,
+loongarch_promote_function_mode (const_tree type,
machine_mode mode,
- int *punsignedp ATTRIBUTE_UNUSED,
+ int *punsignedp,
const_tree fntype ATTRIBUTE_UNUSED,
int for_return ATTRIBUTE_UNUSED)
{
@@ -11154,6 +11154,34 @@ loongarch_c_mode_for_suffix (char suffix)
return VOIDmode;
}
+/* Implement TARGET_C_BITINT_TYPE_INFO.
+ Return true if _BitInt(N) is supported and fill its details into *INFO. */
+bool
+loongarch_bitint_type_info (int n, struct bitint_info *info)
+{
+ if (n <= 8)
+ info->limb_mode = QImode;
+ else if (n <= 16)
+ info->limb_mode = HImode;
+ else if (n <= 32)
+ info->limb_mode = SImode;
+ else if (n <= 64)
+ info->limb_mode = DImode;
+ else if (n <= 128)
+ info->limb_mode = TImode;
+ else
+ info->limb_mode = DImode;
+
+ info->abi_limb_mode = info->limb_mode;
+
+ if (n > 64)
+ info->abi_limb_mode = TImode;
+
+ info->big_endian = false;
+ info->extended = true;
+ return true;
+}
+
/* Initialize the GCC target structure. */
#undef TARGET_ASM_ALIGNED_HI_OP
#define TARGET_ASM_ALIGNED_HI_OP "\t.half\t"
@@ -11428,6 +11456,9 @@ loongarch_c_mode_for_suffix (char suffix)
#undef TARGET_C_MODE_FOR_SUFFIX
#define TARGET_C_MODE_FOR_SUFFIX loongarch_c_mode_for_suffix
+#undef TARGET_C_BITINT_TYPE_INFO
+#define TARGET_C_BITINT_TYPE_INFO loongarch_bitint_type_info
+
struct gcc_target targetm = TARGET_INITIALIZER;
#include "gt-loongarch.h"
diff --git a/gcc/config/loongarch/loongarch.h b/gcc/config/loongarch/loongarch.h
index 5fc86652f5f8..e8819bf14801 100644
--- a/gcc/config/loongarch/loongarch.h
+++ b/gcc/config/loongarch/loongarch.h
@@ -270,7 +270,9 @@ along with GCC; see the file COPYING3. If not see
if (GET_MODE_CLASS (MODE) == MODE_INT \
&& GET_MODE_SIZE (MODE) < UNITS_PER_WORD) \
{ \
- if ((MODE) == SImode) \
+ if ((MODE) == SImode \
+ && !(TYPE && TREE_CODE (TYPE) == BITINT_TYPE \
+ && TYPE_PRECISION (TYPE) < 32)) \
(UNSIGNEDP) = 0; \
(MODE) = Pmode; \
}
diff --git a/gcc/testsuite/gcc.target/loongarch/bitint-alignments.c
b/gcc/testsuite/gcc.target/loongarch/bitint-alignments.c
new file mode 100644
index 000000000000..8592279b038b
--- /dev/null
+++ b/gcc/testsuite/gcc.target/loongarch/bitint-alignments.c
@@ -0,0 +1,58 @@
+/* { dg-do run { target bitint } } */
+/* { dg-additional-options "-std=c23" } */
+
+static long unsigned int
+calc_alignof (int n)
+{
+ if (n > 64)
+ return alignof(__int128_t);
+ if (n > 32)
+ return alignof(long long);
+ if (n > 16)
+ return alignof(int);
+ if (n > 8)
+ return alignof(short);
+ else
+ return alignof(char);
+}
+
+#define CHECK_ALIGNMENT(N) \
+ if (alignof(_BitInt(N)) != calc_alignof(N)) \
+ __builtin_abort ();
+
+int main (void)
+{
+ CHECK_ALIGNMENT(2);
+ CHECK_ALIGNMENT(3);
+ CHECK_ALIGNMENT(7);
+ CHECK_ALIGNMENT(8);
+ CHECK_ALIGNMENT(9);
+ CHECK_ALIGNMENT(13);
+ CHECK_ALIGNMENT(15);
+ CHECK_ALIGNMENT(16);
+ CHECK_ALIGNMENT(17);
+ CHECK_ALIGNMENT(24);
+ CHECK_ALIGNMENT(31);
+ CHECK_ALIGNMENT(32);
+ CHECK_ALIGNMENT(33);
+ CHECK_ALIGNMENT(42);
+ CHECK_ALIGNMENT(53);
+ CHECK_ALIGNMENT(63);
+ CHECK_ALIGNMENT(64);
+ CHECK_ALIGNMENT(65);
+ CHECK_ALIGNMENT(79);
+ CHECK_ALIGNMENT(96);
+ CHECK_ALIGNMENT(113);
+ CHECK_ALIGNMENT(127);
+ CHECK_ALIGNMENT(128);
+ CHECK_ALIGNMENT(129);
+ CHECK_ALIGNMENT(153);
+ CHECK_ALIGNMENT(255);
+ CHECK_ALIGNMENT(256);
+ CHECK_ALIGNMENT(257);
+ CHECK_ALIGNMENT(353);
+ CHECK_ALIGNMENT(512);
+ CHECK_ALIGNMENT(620);
+ CHECK_ALIGNMENT(1024);
+ CHECK_ALIGNMENT(30000);
+}
diff --git a/gcc/testsuite/gcc.target/loongarch/bitint-args.c
b/gcc/testsuite/gcc.target/loongarch/bitint-args.c
new file mode 100644
index 000000000000..ceba1fb6e3af
--- /dev/null
+++ b/gcc/testsuite/gcc.target/loongarch/bitint-args.c
@@ -0,0 +1,81 @@
+/* { dg-do compile { target bitint } } */
+/* { dg-additional-options "-std=c23 -O -fno-stack-clash-protection -g" } */
+/* { dg-final { check-function-bodies "**" "" } } */
+
+#define CHECK_ARG(N) \
+void f##N(_BitInt(N) *ptr, _BitInt(N) y) \
+{ \
+ *ptr = y; \
+}
+
+
+CHECK_ARG(2)
+/*
+** f2:
+** st.b \$r5,\$r4,0
+** jr \$r1
+*/
+CHECK_ARG(8)
+/*
+** f8:
+** st.b \$r5,\$r4,0
+** jr \$r1
+*/
+CHECK_ARG(9)
+/*
+** f9:
+** st.h \$r5,\$r4,0
+** jr \$r1
+*/
+CHECK_ARG(16)
+/*
+** f16:
+** st.h \$r5,\$r4,0
+** jr \$r1
+*/
+CHECK_ARG(19)
+/*
+** f19:
+** stptr.w \$r5,\$r4,0
+** jr \$r1
+*/
+CHECK_ARG(32)
+/*
+** f32:
+** stptr.w \$r5,\$r4,0
+** jr \$r1
+*/
+CHECK_ARG(42)
+/*
+** f42:
+** stptr.d \$r5,\$r4,0
+** jr \$r1
+*/
+CHECK_ARG(64)
+/*
+** f64:
+** stptr.d \$r5,\$r4,0
+** jr \$r1
+*/
+CHECK_ARG(65)
+/*
+** f65:
+** stptr.d \$r5,\$r4,0
+** st.d \$r6,\$r4,8
+** jr \$r1
+*/
+CHECK_ARG(127)
+/*
+** f127:
+** stptr.d \$r5,\$r4,0
+** st.d \$r6,\$r4,8
+** jr \$r1
+*/
+
+CHECK_ARG(128)
+/*
+** f128:
+** stptr.d \$r5,\$r4,0
+** st.d \$r6,\$r4,8
+** jr \$r1
+*/
diff --git a/gcc/testsuite/gcc.target/loongarch/bitint-sizes.c
b/gcc/testsuite/gcc.target/loongarch/bitint-sizes.c
new file mode 100644
index 000000000000..7272f98acbb0
--- /dev/null
+++ b/gcc/testsuite/gcc.target/loongarch/bitint-sizes.c
@@ -0,0 +1,60 @@
+/* { dg-do run { target bitint } } */
+/* { dg-additional-options "-std=c23" } */
+
+static long unsigned int
+calc_size (int n)
+{
+ if (n > 128)
+ return ((n - 1)/128 + 1) * sizeof(__int128_t);
+ if (n > 64)
+ return sizeof(__int128_t);
+ if (n > 32)
+ return sizeof(long long);
+ if (n > 16)
+ return sizeof(int);
+ if (n > 8)
+ return sizeof(short);
+ else
+ return sizeof(char);
+}
+
+#define CHECK_SIZE(N) \
+ if (sizeof(_BitInt(N)) != calc_size(N)) \
+ __builtin_abort ();
+
+int main (void)
+{
+ CHECK_SIZE(2);
+ CHECK_SIZE(3);
+ CHECK_SIZE(7);
+ CHECK_SIZE(8);
+ CHECK_SIZE(9);
+ CHECK_SIZE(13);
+ CHECK_SIZE(15);
+ CHECK_SIZE(16);
+ CHECK_SIZE(17);
+ CHECK_SIZE(24);
+ CHECK_SIZE(31);
+ CHECK_SIZE(32);
+ CHECK_SIZE(33);
+ CHECK_SIZE(42);
+ CHECK_SIZE(53);
+ CHECK_SIZE(63);
+ CHECK_SIZE(64);
+ CHECK_SIZE(65);
+ CHECK_SIZE(79);
+ CHECK_SIZE(96);
+ CHECK_SIZE(113);
+ CHECK_SIZE(127);
+ CHECK_SIZE(128);
+ CHECK_SIZE(129);
+ CHECK_SIZE(153);
+ CHECK_SIZE(255);
+ CHECK_SIZE(256);
+ CHECK_SIZE(257);
+ CHECK_SIZE(353);
+ CHECK_SIZE(512);
+ CHECK_SIZE(620);
+ CHECK_SIZE(1024);
+ CHECK_SIZE(30000);
+}
diff --git a/libgcc/config/loongarch/libgcc-loongarch.ver
b/libgcc/config/loongarch/libgcc-loongarch.ver
new file mode 100644
index 000000000000..0a71f2ecca2f
--- /dev/null
+++ b/libgcc/config/loongarch/libgcc-loongarch.ver
@@ -0,0 +1,28 @@
+# Copyright (C) 2025 Free Software Foundation, Inc.
+#
+# This file is part of GCC.
+#
+# GCC is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+#
+# GCC is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3. If not see
+# <http://www.gnu.org/licenses/>.
+
+GCC_16.0.0 {
+ __mulbitint3
+ __divmodbitint4
+ __fixsfbitint
+ __fixdfbitint
+ __fixtfbitint
+ __floatbitintsf
+ __floatbitintdf
+ __floatbitinttf
+}
diff --git a/libgcc/config/loongarch/t-loongarch
b/libgcc/config/loongarch/t-loongarch
index 2a7dbf6ca83a..b9374fc70016 100644
--- a/libgcc/config/loongarch/t-loongarch
+++ b/libgcc/config/loongarch/t-loongarch
@@ -5,3 +5,5 @@ softfp_int_modes := si di
softfp_extensions :=
softfp_truncations :=
softfp_exclude_libgcc2 := n
+
+SHLIB_MAPFILES += $(srcdir)/config/loongarch/libgcc-loongarch.ver
diff --git a/libgcc/config/loongarch/t-softfp-tf
b/libgcc/config/loongarch/t-softfp-tf
index 306677b12554..be2b7302941c 100644
--- a/libgcc/config/loongarch/t-softfp-tf
+++ b/libgcc/config/loongarch/t-softfp-tf
@@ -1,3 +1,4 @@
softfp_float_modes += tf
softfp_extensions += sftf dftf
softfp_truncations += tfsf tfdf
+softfp_extras += floatbitinttf fixtfbitint
