__riscv_vsetvlmax_e64m1 & co not available with attribute target arch=+v

[dzaima]

Copying out of #56592:

The following fails to compile with -march=rv64gc, despite working with -march=rv64gcv, which should be what the __attribute__ achieves:

#include<riscv_vector.h>

__attribute__((target("arch=+v")))
int vl_e64m1() {
    return __riscv_vsetvlmax_e64m1();
}

https://godbolt.org/z/rPnh5zYE5

I believe this would be because these definitions are preprocessor-gated:

llvm-project/clang/include/clang/Basic/riscv_vector.td

Lines 637 to 675 in 33c42f8

	#if __riscv_v_elen >= 64
	#define __riscv_vsetvl_e8mf8(avl) __builtin_rvv_vsetvli((size_t)(avl), 0, 5)
	#define __riscv_vsetvl_e16mf4(avl) __builtin_rvv_vsetvli((size_t)(avl), 1, 6)
	#define __riscv_vsetvl_e32mf2(avl) __builtin_rvv_vsetvli((size_t)(avl), 2, 7)
	#define __riscv_vsetvl_e64m1(avl) __builtin_rvv_vsetvli((size_t)(avl), 3, 0)
	#define __riscv_vsetvl_e64m2(avl) __builtin_rvv_vsetvli((size_t)(avl), 3, 1)
	#define __riscv_vsetvl_e64m4(avl) __builtin_rvv_vsetvli((size_t)(avl), 3, 2)
	#define __riscv_vsetvl_e64m8(avl) __builtin_rvv_vsetvli((size_t)(avl), 3, 3)
	#endif
	#define __riscv_vsetvlmax_e8mf4() __builtin_rvv_vsetvlimax(0, 6)
	#define __riscv_vsetvlmax_e8mf2() __builtin_rvv_vsetvlimax(0, 7)
	#define __riscv_vsetvlmax_e8m1() __builtin_rvv_vsetvlimax(0, 0)
	#define __riscv_vsetvlmax_e8m2() __builtin_rvv_vsetvlimax(0, 1)
	#define __riscv_vsetvlmax_e8m4() __builtin_rvv_vsetvlimax(0, 2)
	#define __riscv_vsetvlmax_e8m8() __builtin_rvv_vsetvlimax(0, 3)
	#define __riscv_vsetvlmax_e16mf2() __builtin_rvv_vsetvlimax(1, 7)
	#define __riscv_vsetvlmax_e16m1() __builtin_rvv_vsetvlimax(1, 0)
	#define __riscv_vsetvlmax_e16m2() __builtin_rvv_vsetvlimax(1, 1)
	#define __riscv_vsetvlmax_e16m4() __builtin_rvv_vsetvlimax(1, 2)
	#define __riscv_vsetvlmax_e16m8() __builtin_rvv_vsetvlimax(1, 3)
	#define __riscv_vsetvlmax_e32m1() __builtin_rvv_vsetvlimax(2, 0)
	#define __riscv_vsetvlmax_e32m2() __builtin_rvv_vsetvlimax(2, 1)
	#define __riscv_vsetvlmax_e32m4() __builtin_rvv_vsetvlimax(2, 2)
	#define __riscv_vsetvlmax_e32m8() __builtin_rvv_vsetvlimax(2, 3)
	#if __riscv_v_elen >= 64
	#define __riscv_vsetvlmax_e8mf8() __builtin_rvv_vsetvlimax(0, 5)
	#define __riscv_vsetvlmax_e16mf4() __builtin_rvv_vsetvlimax(1, 6)
	#define __riscv_vsetvlmax_e32mf2() __builtin_rvv_vsetvlimax(2, 7)
	#define __riscv_vsetvlmax_e64m1() __builtin_rvv_vsetvlimax(3, 0)
	#define __riscv_vsetvlmax_e64m2() __builtin_rvv_vsetvlimax(3, 1)
	#define __riscv_vsetvlmax_e64m4() __builtin_rvv_vsetvlimax(3, 2)
	#define __riscv_vsetvlmax_e64m8() __builtin_rvv_vsetvlimax(3, 3)
	#endif

[llvmbot]

@llvm/issue-subscribers-backend-risc-v

Author: dzaima (dzaima)

Copying out of https://github.com//issues/56592:

The following fails to compile with -march=rv64gc, despite working with -march=rv64gcv, which should be what the __attribute__ achieves:

#include<riscv_vector.h>

__attribute__((target("arch=+v")))
int vl_e64m1() {
    return __riscv_vsetvlmax_e64m1();
}

https://godbolt.org/z/rPnh5zYE5

I believe this would be because these definitions are preprocessor-gated:

llvm-project/clang/include/clang/Basic/riscv_vector.td

Lines 637 to 675 in 33c42f8

	#if __riscv_v_elen >= 64
	#define __riscv_vsetvl_e8mf8(avl) __builtin_rvv_vsetvli((size_t)(avl), 0, 5)
	#define __riscv_vsetvl_e16mf4(avl) __builtin_rvv_vsetvli((size_t)(avl), 1, 6)
	#define __riscv_vsetvl_e32mf2(avl) __builtin_rvv_vsetvli((size_t)(avl), 2, 7)
	#define __riscv_vsetvl_e64m1(avl) __builtin_rvv_vsetvli((size_t)(avl), 3, 0)
	#define __riscv_vsetvl_e64m2(avl) __builtin_rvv_vsetvli((size_t)(avl), 3, 1)
	#define __riscv_vsetvl_e64m4(avl) __builtin_rvv_vsetvli((size_t)(avl), 3, 2)
	#define __riscv_vsetvl_e64m8(avl) __builtin_rvv_vsetvli((size_t)(avl), 3, 3)
	#endif
	#define __riscv_vsetvlmax_e8mf4() __builtin_rvv_vsetvlimax(0, 6)
	#define __riscv_vsetvlmax_e8mf2() __builtin_rvv_vsetvlimax(0, 7)
	#define __riscv_vsetvlmax_e8m1() __builtin_rvv_vsetvlimax(0, 0)
	#define __riscv_vsetvlmax_e8m2() __builtin_rvv_vsetvlimax(0, 1)
	#define __riscv_vsetvlmax_e8m4() __builtin_rvv_vsetvlimax(0, 2)
	#define __riscv_vsetvlmax_e8m8() __builtin_rvv_vsetvlimax(0, 3)
	#define __riscv_vsetvlmax_e16mf2() __builtin_rvv_vsetvlimax(1, 7)
	#define __riscv_vsetvlmax_e16m1() __builtin_rvv_vsetvlimax(1, 0)
	#define __riscv_vsetvlmax_e16m2() __builtin_rvv_vsetvlimax(1, 1)
	#define __riscv_vsetvlmax_e16m4() __builtin_rvv_vsetvlimax(1, 2)
	#define __riscv_vsetvlmax_e16m8() __builtin_rvv_vsetvlimax(1, 3)
	#define __riscv_vsetvlmax_e32m1() __builtin_rvv_vsetvlimax(2, 0)
	#define __riscv_vsetvlmax_e32m2() __builtin_rvv_vsetvlimax(2, 1)
	#define __riscv_vsetvlmax_e32m4() __builtin_rvv_vsetvlimax(2, 2)
	#define __riscv_vsetvlmax_e32m8() __builtin_rvv_vsetvlimax(2, 3)
	#if __riscv_v_elen >= 64
	#define __riscv_vsetvlmax_e8mf8() __builtin_rvv_vsetvlimax(0, 5)
	#define __riscv_vsetvlmax_e16mf4() __builtin_rvv_vsetvlimax(1, 6)
	#define __riscv_vsetvlmax_e32mf2() __builtin_rvv_vsetvlimax(2, 7)
	#define __riscv_vsetvlmax_e64m1() __builtin_rvv_vsetvlimax(3, 0)
	#define __riscv_vsetvlmax_e64m2() __builtin_rvv_vsetvlimax(3, 1)
	#define __riscv_vsetvlmax_e64m4() __builtin_rvv_vsetvlimax(3, 2)
	#define __riscv_vsetvlmax_e64m8() __builtin_rvv_vsetvlimax(3, 3)
	#endif

[topperc]

@4vtomat

[4vtomat]

let me take this! thanks @dzaima for reporting!