Do you mind creating a PR to https://github.com/riscv/riscv-elf-psabi-doc/pull/ to start the discussion? I believe this should be documented somewhere since it should be consistent between LLVM and GCC.
On Mon, Nov 4, 2024 at 2:26 PM Zhijin Zeng <zhijin.z...@spacemit.com> wrote: > > I can't find the vector function name mangling of risc-v, so in order to > support TARGET_SIMD_CLONE_COMPUTE_VECSIZE_AND_SIMDLEN, > TARGET_SIMD_CLONE_ADJUST and TARGET_SIMD_CLONE_USABLE, I add risc-v > vector function mangling rules as follow: > > _ZGV<x>N<y>v<v...>_<func_name> > > 'x' is the LMUL, if the LMUL is 1/2/4/8 and 'x' is 1/2/4/8. > 'y' is the count of elements also 'simdlen' in gcc. > 'v...' depends on the number of parameter, there are as many 'v' > characters as there are parameters. > 'func_name' is the scalar function name. > > Maybe it's incorrect or incomplete, but I think it's worhting > discussing. And combined with the glibc patch, we can use libmvec in risc-v. > > glibc patch: > https://inbox.sourceware.org/libc-alpha/af3aceaa-dcf1-4fa6-ad7e-a7fd7444a...@spacemit.com/ > > > Thanks, > > Zhijin > > > diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc > index 0b3b2c4cba9..d181aae4ac7 100644 > --- a/gcc/config/riscv/riscv.cc > +++ b/gcc/config/riscv/riscv.cc > @@ -23,6 +23,7 @@ along with GCC; see the file COPYING3. If not see > > #define INCLUDE_MEMORY > #define INCLUDE_STRING > +#include <cmath> > #include "config.h" > #include "system.h" > #include "coretypes.h" > @@ -34,6 +35,7 @@ along with GCC; see the file COPYING3. If not see > #include "insn-config.h" > #include "insn-attr.h" > #include "recog.h" > +#include "cgraph.h" > #include "output.h" > #include "alias.h" > #include "tree.h" > @@ -5787,7 +5789,9 @@ riscv_vector_type_p (const_tree type) > { > /* Currently, only builtin scalable vector type is allowed, in the > future, > more vector types may be allowed, such as GNU vector type, etc. */ > - return riscv_vector::builtin_type_p (type); > + if (!type) > + return false; > + return riscv_vector::builtin_type_p (type) || VECTOR_TYPE_P (type); > } > > static unsigned int > @@ -12695,6 +12699,231 @@ > riscv_stack_clash_protection_alloca_probe_range (void) > return STACK_CLASH_CALLER_GUARD; > } > > +/* Return true for types that could be supported as SIMD return or > + argument types. */ > + > +static bool > +supported_simd_type (tree t) > +{ > + if (SCALAR_FLOAT_TYPE_P (t) || INTEGRAL_TYPE_P (t)) > + { > + HOST_WIDE_INT s = tree_to_shwi (TYPE_SIZE_UNIT (t)); > + return s == 1 || s == 2 || s == 4 || s == 8; > + } > + return false; > +} > + > +static unsigned > +lane_size (cgraph_simd_clone_arg_type clone_arg_type, tree type) > +{ > + gcc_assert (clone_arg_type != SIMD_CLONE_ARG_TYPE_MASK); > + > + if (INTEGRAL_TYPE_P (type) > + || SCALAR_FLOAT_TYPE_P (type)) > + switch (TYPE_PRECISION (type) / BITS_PER_UNIT) > + { > + default: > + break; > + case 1: > + case 2: > + case 4: > + case 8: > + return TYPE_PRECISION (type); > + } > + gcc_unreachable (); > +} > + > +/* Implement TARGET_SIMD_CLONE_COMPUTE_VECSIZE_AND_SIMDLEN. */ > + > +static int > +riscv_simd_clone_compute_vecsize_and_simdlen (struct cgraph_node *node, > + struct cgraph_simd_clone *clonei, > + tree base_type ATTRIBUTE_UNUSED, > + int num, bool explicit_p) > +{ > + tree t, ret_type; > + unsigned int elt_bit = 0; > + unsigned HOST_WIDE_INT const_simdlen; > + > + if (!TARGET_VECTOR) > + return 0; > + > + if (maybe_ne (clonei->simdlen, 0U) > + && clonei->simdlen.is_constant (&const_simdlen) > + && (const_simdlen < 2 > + || const_simdlen > 1024 > + || (const_simdlen & (const_simdlen - 1)) != 0)) > + { > + if (explicit_p) > + warning_at (DECL_SOURCE_LOCATION (node->decl), 0, > + "unsupported simdlen %wd", const_simdlen); > + return 0; > + } > + > + ret_type = TREE_TYPE (TREE_TYPE (node->decl)); > + if (TREE_CODE (ret_type) != VOID_TYPE > + && !supported_simd_type (ret_type)) > + { > + if (!explicit_p) > + ; > + else if (COMPLEX_FLOAT_TYPE_P (ret_type)) > + warning_at (DECL_SOURCE_LOCATION (node->decl), 0, > + "GCC does not currently support return type %qT " > + "for simd", ret_type); > + else > + warning_at (DECL_SOURCE_LOCATION (node->decl), 0, > + "unsupported return type %qT for simd", > + ret_type); > + return 0; > + } > + > + auto_vec<std::pair <tree, unsigned int>> vec_elts (clonei->nargs + 1); > + if (TREE_CODE (ret_type) != VOID_TYPE) > + { > + elt_bit = lane_size (SIMD_CLONE_ARG_TYPE_VECTOR, ret_type); > + vec_elts.safe_push (std::make_pair (ret_type, elt_bit)); > + } > + > + int i; > + tree type_arg_types = TYPE_ARG_TYPES (TREE_TYPE (node->decl)); > + bool decl_arg_p = (node->definition || type_arg_types == NULL_TREE); > + for (t = (decl_arg_p ? DECL_ARGUMENTS (node->decl) : type_arg_types), > i = 0; > + t && t != void_list_node; t = TREE_CHAIN (t), i++) > + { > + tree arg_type = decl_arg_p ? TREE_TYPE (t) : TREE_VALUE (t); > + if (clonei->args[i].arg_type != SIMD_CLONE_ARG_TYPE_UNIFORM > + && !supported_simd_type (arg_type)) > + { > + if (!explicit_p) > + ; > + else if (COMPLEX_FLOAT_TYPE_P (ret_type)) > + warning_at (DECL_SOURCE_LOCATION (node->decl), 0, > + "GCC does not currently support argument type %qT " > + "for simd", arg_type); > + else > + warning_at (DECL_SOURCE_LOCATION (node->decl), 0, > + "unsupported argument type %qT for simd", > + arg_type); > + return 0; > + } > + unsigned lane_bits = lane_size (clonei->args[i].arg_type, arg_type); > + if (clonei->args[i].arg_type == SIMD_CLONE_ARG_TYPE_VECTOR) > + vec_elts.safe_push (std::make_pair (arg_type, lane_bits)); > + if (!elt_bit) > + elt_bit = lane_bits; > + if (elt_bit != lane_bits) > + return 0; > + } > + > + if (!elt_bit) > + return 0; > + > + clonei->vecsize_mangle = 'n'; > + clonei->mask_mode = VOIDmode; > + poly_uint64 simdlen; > + auto_vec<poly_uint64> simdlens (2); > + > + clonei->vecsize_int = 0; > + clonei->vecsize_float = 0; > + > + if ((unsigned int)TARGET_MIN_VLEN <= elt_bit) > + return 0; > + > + /* Keep track of the possible simdlens the clones of this function > can have, > + and check them later to see if we support them. */ > + if (known_eq (clonei->simdlen, 0U)) > + { > + if (TARGET_MAX_LMUL >= RVV_M1) > + simdlens.safe_push ( > + exact_div (poly_uint64 (TARGET_MIN_VLEN * RVV_M1), elt_bit)); > + if (TARGET_MAX_LMUL >= RVV_M2) > + simdlens.safe_push ( > + exact_div (poly_uint64 (TARGET_MIN_VLEN * RVV_M2), elt_bit)); > + if (TARGET_MAX_LMUL >= RVV_M4) > + simdlens.safe_push ( > + exact_div (poly_uint64 (TARGET_MIN_VLEN * RVV_M4), elt_bit)); > + if (TARGET_MAX_LMUL >= RVV_M8) > + simdlens.safe_push ( > + exact_div (poly_uint64 (TARGET_MIN_VLEN * RVV_M8), elt_bit)); > + } > + else > + simdlens.safe_push (clonei->simdlen); > + > + unsigned j = 0; > + while (j < simdlens.length ()) > + { > + bool remove_simdlen = false; > + for (auto elt : vec_elts) > + if (known_gt (simdlens[j] * elt.second, > + TARGET_MIN_VLEN * TARGET_MAX_LMUL)) > + { > + /* Don't issue a warning for every simdclone when there is no > + specific simdlen clause. */ > + if (explicit_p && maybe_ne (clonei->simdlen, 0U)) > + warning_at (DECL_SOURCE_LOCATION (node->decl), 0, > + "GCC does not currently support simdlen %wd for " > + "type %qT", > + constant_lower_bound (simdlens[j]), elt.first); > + remove_simdlen = true; > + break; > + } > + if (remove_simdlen) > + simdlens.ordered_remove (j); > + else > + j++; > + } > + > + int count = simdlens.length (); > + if (count == 0) > + { > + if (explicit_p && known_eq (clonei->simdlen, 0U)) > + { > + /* Warn the user if we can't generate any simdclone. */ > + //simdlen = exact_div (TARGET_MIN_VLEN * LMUL, elt_bit); > + warning_at (DECL_SOURCE_LOCATION (node->decl), 0, > + "GCC does not currently support a simdclone with > simdlens" > + " %wd and %wd for these types.", > + constant_lower_bound (simdlen), > + constant_lower_bound (simdlen*2)); > + } > + return 0; > + } > + > + gcc_assert (num < count); > + clonei->vecsize_mangle = std::exp2 (num) + '0'; > + clonei->simdlen = simdlens[num]; > + return count; > +} > + > +/* Implement TARGET_SIMD_CLONE_ADJUST. */ > + > +static void > +riscv_simd_clone_adjust (struct cgraph_node *node) > +{ > + tree t = TREE_TYPE (node->decl); > + TYPE_ATTRIBUTES (t) = make_attribute ("riscv_vector_cc", "default", > + TYPE_ATTRIBUTES (t)); > +} > + > +/* Implement TARGET_SIMD_CLONE_USABLE. */ > + > +static int > +riscv_simd_clone_usable (struct cgraph_node *node) > +{ > + switch (node->simdclone->vecsize_mangle) > + { > + case '1': > + case '2': > + case '4': > + case '8': > + if (!TARGET_VECTOR) > + return -1; > + return 0; > + default: > + gcc_unreachable (); > + } > +} > + > /* Initialize the GCC target structure. */ > #undef TARGET_ASM_ALIGNED_HI_OP > #define TARGET_ASM_ALIGNED_HI_OP "\t.half\t" > @@ -13060,6 +13289,16 @@ riscv_stack_clash_protection_alloca_probe_range > (void) > #undef TARGET_C_MODE_FOR_FLOATING_TYPE > #define TARGET_C_MODE_FOR_FLOATING_TYPE riscv_c_mode_for_floating_type > > +#undef TARGET_SIMD_CLONE_COMPUTE_VECSIZE_AND_SIMDLEN > +#define TARGET_SIMD_CLONE_COMPUTE_VECSIZE_AND_SIMDLEN \ > + riscv_simd_clone_compute_vecsize_and_simdlen > + > +#undef TARGET_SIMD_CLONE_ADJUST > +#define TARGET_SIMD_CLONE_ADJUST riscv_simd_clone_adjust > + > +#undef TARGET_SIMD_CLONE_USABLE > +#define TARGET_SIMD_CLONE_USABLE riscv_simd_clone_usable > + > struct gcc_target targetm = TARGET_INITIALIZER; > > #include "gt-riscv.h" > -- > 2.25.1 > > This message and any attachment are confidential and may be privileged or > otherwise protected from disclosure. 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