x86-64: Add vector exp10/exp10f implementation to libmvec

Implement vectorized exp10/exp10f containing SSE, AVX, AVX2 and
AVX512 versions for libmvec as per vector ABI.  It also contains
accuracy and ABI tests for vector exp10/exp10f with regenerated ulps.

Reviewed-by: H.J. Lu <hjl.tools@gmail.com>

1 files changed, 269 insertions, 0 deletions

diff --git a/sysdeps/x86_64/fpu/multiarch/svml_s_exp10f16_core_avx512.S b/sysdeps/x86_64/fpu/multiarch/svml_s_exp10f16_core_avx512.S
new file mode 100644
index 0000000000..fc9309c90f
--- /dev/null
+++ b/sysdeps/x86_64/fpu/multiarch/svml_s_exp10f16_core_avx512.S
@@ -0,0 +1,269 @@
+/* Function exp10f vectorized with AVX-512.
+   Copyright (C) 2021 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   https://www.gnu.org/licenses/.  */
+
+/*
+ * ALGORITHM DESCRIPTION:
+ *   Typical exp10() implementation, except that:
+ *    - tables are small (16 elements), allowing for fast gathers
+ *    - all arguments processed in the main path
+ *        - final VSCALEF assists branch-free design (correct overflow/underflow and special case responses)
+ *        - a VAND is used to ensure the reduced argument |R|<2, even for large inputs
+ *        - RZ mode used to avoid oveflow to +/-Inf for x*log2(e); helps with special case handling
+ *        - SAE used to avoid spurious flag settings
+ *
+ */
+
+/* Offsets for data table __svml_sexp10_data_internal_avx512
+ */
+#define Exp_tbl_L                     	0
+#define Exp_tbl_H                     	128
+#define L2E                           	256
+#define Shifter                       	320
+#define L2H                           	384
+#define L2L                           	448
+#define EMask                         	512
+#define AbsMask                       	576
+#define Threshold                     	640
+#define poly_coeff2                   	704
+#define poly_coeff1                   	768
+
+#include <sysdep.h>
+
+        .text
+	.section .text.exex512,"ax",@progbits
+ENTRY(_ZGVeN16v_exp10f_skx)
+        pushq     %rbp
+        cfi_def_cfa_offset(16)
+        movq      %rsp, %rbp
+        cfi_def_cfa(6, 16)
+        cfi_offset(6, -16)
+        andq      $-64, %rsp
+        subq      $192, %rsp
+        vmovups   L2E+__svml_sexp10_data_internal_avx512(%rip), %zmm2
+        vmovups   Shifter+__svml_sexp10_data_internal_avx512(%rip), %zmm1
+        vmovups   L2H+__svml_sexp10_data_internal_avx512(%rip), %zmm5
+        vmovups   L2L+__svml_sexp10_data_internal_avx512(%rip), %zmm4
+
+/* ensure |R|<2 even for special cases */
+        vmovups   EMask+__svml_sexp10_data_internal_avx512(%rip), %zmm6
+        vmovups   poly_coeff2+__svml_sexp10_data_internal_avx512(%rip), %zmm9
+
+/* 2^(52-4)*1.5 + x * log2(e) */
+        vfmadd213ps {rz-sae}, %zmm1, %zmm0, %zmm2
+        vmovups   poly_coeff1+__svml_sexp10_data_internal_avx512(%rip), %zmm10
+        vmovups   __svml_sexp10_data_internal_avx512(%rip), %zmm8
+        vmovups   Exp_tbl_H+__svml_sexp10_data_internal_avx512(%rip), %zmm15
+        vmovups   Threshold+__svml_sexp10_data_internal_avx512(%rip), %zmm13
+        vpsrld    $5, %zmm2, %zmm3
+
+/* Z0 ~ x*log2(e), rounded down to 6 fractional bits */
+        vsubps    {rn-sae}, %zmm1, %zmm2, %zmm1
+        vpermt2ps Exp_tbl_L+64+__svml_sexp10_data_internal_avx512(%rip), %zmm2, %zmm8
+        vpermt2ps Exp_tbl_H+64+__svml_sexp10_data_internal_avx512(%rip), %zmm3, %zmm15
+        vandps    AbsMask+__svml_sexp10_data_internal_avx512(%rip), %zmm0, %zmm12
+
+/* R = x - Z0*log(2) */
+        vfnmadd213ps {rn-sae}, %zmm0, %zmm1, %zmm5
+        vcmpps    $29, {sae}, %zmm13, %zmm12, %k0
+        vfnmadd231ps {rn-sae}, %zmm1, %zmm4, %zmm5
+        kmovw     %k0, %edx
+        vrangeps  $2, {sae}, %zmm6, %zmm5, %zmm11
+        vfmadd231ps {rn-sae}, %zmm11, %zmm9, %zmm10
+        vmulps    {rn-sae}, %zmm11, %zmm10, %zmm14
+
+/* x!=0? */
+        vpxord    %zmm7, %zmm7, %zmm7
+        vcmpps    $4, {sae}, %zmm7, %zmm0, %k1
+
+/* Th*Tl */
+        vmulps    {rn-sae}, %zmm8, %zmm15, %zmm15{%k1}
+        vfmadd213ps {rn-sae}, %zmm15, %zmm14, %zmm15
+        vscalefps {rn-sae}, %zmm1, %zmm15, %zmm1
+        testl     %edx, %edx
+
+/* Go to special inputs processing branch */
+        jne       L(SPECIAL_VALUES_BRANCH)
+                                # LOE rbx r12 r13 r14 r15 edx zmm0 zmm1
+
+/* Restore registers
+ * and exit the function
+ */
+
+L(EXIT):
+        vmovaps   %zmm1, %zmm0
+        movq      %rbp, %rsp
+        popq      %rbp
+        cfi_def_cfa(7, 8)
+        cfi_restore(6)
+        ret
+        cfi_def_cfa(6, 16)
+        cfi_offset(6, -16)
+
+/* Branch to process
+ * special inputs
+ */
+
+L(SPECIAL_VALUES_BRANCH):
+        vmovups   %zmm0, 64(%rsp)
+        vmovups   %zmm1, 128(%rsp)
+                                # LOE rbx r12 r13 r14 r15 edx zmm1
+
+        xorl      %eax, %eax
+                                # LOE rbx r12 r13 r14 r15 eax edx
+
+        vzeroupper
+        movq      %r12, 16(%rsp)
+        /*  DW_CFA_expression: r12 (r12) (DW_OP_lit8; DW_OP_minus; DW_OP_const4s: -64; DW_OP_and; DW_OP_const4s: -176; DW_OP_plus)  */
+        .cfi_escape 0x10, 0x0c, 0x0e, 0x38, 0x1c, 0x0d, 0xc0, 0xff, 0xff, 0xff, 0x1a, 0x0d, 0x50, 0xff, 0xff, 0xff, 0x22
+        movl      %eax, %r12d
+        movq      %r13, 8(%rsp)
+        /*  DW_CFA_expression: r13 (r13) (DW_OP_lit8; DW_OP_minus; DW_OP_const4s: -64; DW_OP_and; DW_OP_const4s: -184; DW_OP_plus)  */
+        .cfi_escape 0x10, 0x0d, 0x0e, 0x38, 0x1c, 0x0d, 0xc0, 0xff, 0xff, 0xff, 0x1a, 0x0d, 0x48, 0xff, 0xff, 0xff, 0x22
+        movl      %edx, %r13d
+        movq      %r14, (%rsp)
+        /*  DW_CFA_expression: r14 (r14) (DW_OP_lit8; DW_OP_minus; DW_OP_const4s: -64; DW_OP_and; DW_OP_const4s: -192; DW_OP_plus)  */
+        .cfi_escape 0x10, 0x0e, 0x0e, 0x38, 0x1c, 0x0d, 0xc0, 0xff, 0xff, 0xff, 0x1a, 0x0d, 0x40, 0xff, 0xff, 0xff, 0x22
+                                # LOE rbx r15 r12d r13d
+
+/* Range mask
+ * bits check
+ */
+
+L(RANGEMASK_CHECK):
+        btl       %r12d, %r13d
+
+/* Call scalar math function */
+        jc        L(SCALAR_MATH_CALL)
+                                # LOE rbx r15 r12d r13d
+
+/* Special inputs
+ * processing loop
+ */
+
+L(SPECIAL_VALUES_LOOP):
+        incl      %r12d
+        cmpl      $16, %r12d
+
+/* Check bits in range mask */
+        jl        L(RANGEMASK_CHECK)
+                                # LOE rbx r15 r12d r13d
+
+        movq      16(%rsp), %r12
+        cfi_restore(12)
+        movq      8(%rsp), %r13
+        cfi_restore(13)
+        movq      (%rsp), %r14
+        cfi_restore(14)
+        vmovups   128(%rsp), %zmm1
+
+/* Go to exit */
+        jmp       L(EXIT)
+        /*  DW_CFA_expression: r12 (r12) (DW_OP_lit8; DW_OP_minus; DW_OP_const4s: -64; DW_OP_and; DW_OP_const4s: -176; DW_OP_plus)  */
+        .cfi_escape 0x10, 0x0c, 0x0e, 0x38, 0x1c, 0x0d, 0xc0, 0xff, 0xff, 0xff, 0x1a, 0x0d, 0x50, 0xff, 0xff, 0xff, 0x22
+        /*  DW_CFA_expression: r13 (r13) (DW_OP_lit8; DW_OP_minus; DW_OP_const4s: -64; DW_OP_and; DW_OP_const4s: -184; DW_OP_plus)  */
+        .cfi_escape 0x10, 0x0d, 0x0e, 0x38, 0x1c, 0x0d, 0xc0, 0xff, 0xff, 0xff, 0x1a, 0x0d, 0x48, 0xff, 0xff, 0xff, 0x22
+        /*  DW_CFA_expression: r14 (r14) (DW_OP_lit8; DW_OP_minus; DW_OP_const4s: -64; DW_OP_and; DW_OP_const4s: -192; DW_OP_plus)  */
+        .cfi_escape 0x10, 0x0e, 0x0e, 0x38, 0x1c, 0x0d, 0xc0, 0xff, 0xff, 0xff, 0x1a, 0x0d, 0x40, 0xff, 0xff, 0xff, 0x22
+                                # LOE rbx r12 r13 r14 r15 zmm1
+
+/* Scalar math fucntion call
+ * to process special input
+ */
+
+L(SCALAR_MATH_CALL):
+        movl      %r12d, %r14d
+        movss     64(%rsp,%r14,4), %xmm0
+        call      exp10f@PLT
+                                # LOE rbx r14 r15 r12d r13d xmm0
+
+        movss     %xmm0, 128(%rsp,%r14,4)
+
+/* Process special inputs in loop */
+        jmp       L(SPECIAL_VALUES_LOOP)
+                                # LOE rbx r15 r12d r13d
+END(_ZGVeN16v_exp10f_skx)
+
+        .section .rodata, "a"
+        .align 64
+
+#ifdef __svml_sexp10_data_internal_avx512_typedef
+typedef unsigned int VUINT32;
+typedef struct {
+        __declspec(align(64)) VUINT32 Exp_tbl_L[32][1];
+        __declspec(align(64)) VUINT32 Exp_tbl_H[32][1];
+        __declspec(align(64)) VUINT32 L2E[16][1];
+        __declspec(align(64)) VUINT32 Shifter[16][1];
+        __declspec(align(64)) VUINT32 L2H[16][1];
+        __declspec(align(64)) VUINT32 L2L[16][1];
+        __declspec(align(64)) VUINT32 EMask[16][1];
+        __declspec(align(64)) VUINT32 AbsMask[16][1];
+        __declspec(align(64)) VUINT32 Threshold[16][1];
+        __declspec(align(64)) VUINT32 poly_coeff2[16][1];
+        __declspec(align(64)) VUINT32 poly_coeff1[16][1];
+    } __svml_sexp10_data_internal_avx512;
+#endif
+__svml_sexp10_data_internal_avx512:
+        /*== Exp_tbl_L ==*/
+        .long 0x3f800001, 0x3f801631, 0x3f802c65, 0x3f80429d
+        .long 0x3f8058d9, 0x3f806f18, 0x3f80855c, 0x3f809ba3
+        .long 0x3f80b1ee, 0x3f80c83d, 0x3f80de90, 0x3f80f4e7
+        .long 0x3f810b42, 0x3f8121a0, 0x3f813803, 0x3f814e69
+        .long 0x3f8164d3, 0x3f817b41, 0x3f8191b3, 0x3f81a829
+        .long 0x3f81bea2, 0x3f81d520, 0x3f81eba2, 0x3f820227
+        .long 0x3f8218b0, 0x3f822f3d, 0x3f8245cf, 0x3f825c64
+        .long 0x3f8272fd, 0x3f828999, 0x3f82a03a, 0x3f82b6df
+        /*== Exp_tbl_H ==*/
+        .align 64
+        .long 0x3f800000, 0x3f82cd87, 0x3f85aac3, 0x3f88980f
+        .long 0x3f8b95c2, 0x3f8ea43a, 0x3f91c3d3, 0x3f94f4f0
+        .long 0x3f9837f0, 0x3f9b8d3a, 0x3f9ef532, 0x3fa27043
+        .long 0x3fa5fed7, 0x3fa9a15b, 0x3fad583f, 0x3fb123f6
+        .long 0x3fb504f3, 0x3fb8fbaf, 0x3fbd08a4, 0x3fc12c4d
+        .long 0x3fc5672a, 0x3fc9b9be, 0x3fce248c, 0x3fd2a81e
+        .long 0x3fd744fd, 0x3fdbfbb8, 0x3fe0ccdf, 0x3fe5b907
+        .long 0x3feac0c7, 0x3fefe4ba, 0x3ff5257d, 0x3ffa83b3
+        /*== log2(10) ==*/
+        .align 64
+        .long 0x40549A78, 0x40549A78, 0x40549A78, 0x40549A78, 0x40549A78, 0x40549A78, 0x40549A78, 0x40549A78, 0x40549A78, 0x40549A78, 0x40549A78, 0x40549A78, 0x40549A78, 0x40549A78, 0x40549A78, 0x40549A78
+        /*== Shifter=2^(23-10)*1.5 ==*/
+        .align 64
+        .long 0x46400000, 0x46400000, 0x46400000, 0x46400000, 0x46400000, 0x46400000, 0x46400000, 0x46400000, 0x46400000, 0x46400000, 0x46400000, 0x46400000, 0x46400000, 0x46400000, 0x46400000, 0x46400000
+        /*== L2H = log(2)_high ==*/
+        .align 64
+        .long 0x3e9a209b, 0x3e9a209b, 0x3e9a209b, 0x3e9a209b, 0x3e9a209b, 0x3e9a209b, 0x3e9a209b, 0x3e9a209b, 0x3e9a209b, 0x3e9a209b, 0x3e9a209b, 0x3e9a209b, 0x3e9a209b, 0x3e9a209b, 0x3e9a209b, 0x3e9a209b
+        /*== L2L = log(2)_low ==*/
+        .align 64
+        .long 0xb2760860, 0xb2760860, 0xb2760860, 0xb2760860, 0xb2760860, 0xb2760860, 0xb2760860, 0xb2760860, 0xb2760860, 0xb2760860, 0xb2760860, 0xb2760860, 0xb2760860, 0xb2760860, 0xb2760860, 0xb2760860
+        /*== EMask ==*/
+        .align 64
+        .long 0x3f000000, 0x3f000000, 0x3f000000, 0x3f000000, 0x3f000000, 0x3f000000, 0x3f000000, 0x3f000000, 0x3f000000, 0x3f000000, 0x3f000000, 0x3f000000, 0x3f000000, 0x3f000000, 0x3f000000, 0x3f000000
+        /*== AbsMask ==*/
+        .align 64
+        .long 0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff
+        /*== Threshold ==*/
+        .align 64
+        .long 0x4217B818, 0x4217B818, 0x4217B818, 0x4217B818, 0x4217B818, 0x4217B818, 0x4217B818, 0x4217B818, 0x4217B818, 0x4217B818, 0x4217B818, 0x4217B818, 0x4217B818, 0x4217B818, 0x4217B818, 0x4217B818
+        /*== poly_coeff2 ==*/
+        .align 64
+        .long 0x4029B7DA, 0x4029B7DA, 0x4029B7DA, 0x4029B7DA, 0x4029B7DA, 0x4029B7DA, 0x4029B7DA, 0x4029B7DA, 0x4029B7DA, 0x4029B7DA, 0x4029B7DA, 0x4029B7DA, 0x4029B7DA, 0x4029B7DA, 0x4029B7DA, 0x4029B7DA
+        /*== poly_coeff1 ==*/
+        .align 64
+        .long 0x40135D8D, 0x40135D8D, 0x40135D8D, 0x40135D8D, 0x40135D8D, 0x40135D8D, 0x40135D8D, 0x40135D8D, 0x40135D8D, 0x40135D8D, 0x40135D8D, 0x40135D8D, 0x40135D8D, 0x40135D8D, 0x40135D8D, 0x40135D8D
+        .align 64
+        .type	__svml_sexp10_data_internal_avx512,@object
+        .size	__svml_sexp10_data_internal_avx512,.-__svml_sexp10_data_internal_avx512