From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 7844) id 2B355384145F; Thu, 9 Jun 2022 20:38:22 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 2B355384145F Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Noah Goldstein To: glibc-cvs@sourceware.org Subject: [glibc] x86: Improve svml_s_atanhf4_core_sse4.S X-Act-Checkin: glibc X-Git-Author: Noah Goldstein X-Git-Refname: refs/heads/master X-Git-Oldrev: 65897e991685c87f4575694197d3ce24f7fc9c5a X-Git-Newrev: fe1915d4f6dd5db92ce9d0be47c9d4e04f95946c Message-Id: <20220609203822.2B355384145F@sourceware.org> Date: Thu, 9 Jun 2022 20:38:22 +0000 (GMT) X-BeenThere: glibc-cvs@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Glibc-cvs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 09 Jun 2022 20:38:22 -0000 https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=fe1915d4f6dd5db92ce9d0be47c9d4e04f95946c commit fe1915d4f6dd5db92ce9d0be47c9d4e04f95946c Author: Noah Goldstein Date: Thu Jun 9 09:58:31 2022 -0700 x86: Improve svml_s_atanhf4_core_sse4.S Improvements are: 1. Reduce code size (-62 bytes). 2. Remove redundant move instructions. 3. Slightly improve instruction selection/scheduling where possible. 4. Prefer registers which get short instruction encoding. 5. Reduce rodata usage (-16 bytes). The throughput improvement is not significant as the port 0 bottleneck is unavoidable. Function, New Time, Old Time, New / Old _ZGVbN4v_atanhf, 8.821, 8.903, 0.991 Diff: --- .../fpu/multiarch/svml_s_atanhf4_core_sse4.S | 378 +++++++++------------ 1 file changed, 169 insertions(+), 209 deletions(-) diff --git a/sysdeps/x86_64/fpu/multiarch/svml_s_atanhf4_core_sse4.S b/sysdeps/x86_64/fpu/multiarch/svml_s_atanhf4_core_sse4.S index 2d3ad2617f..37200b3601 100644 --- a/sysdeps/x86_64/fpu/multiarch/svml_s_atanhf4_core_sse4.S +++ b/sysdeps/x86_64/fpu/multiarch/svml_s_atanhf4_core_sse4.S @@ -30,96 +30,80 @@ * */ -/* Offsets for data table __svml_satanh_data_internal - */ -#define SgnMask 0 -#define sOne 16 -#define sPoly 32 -#define iBrkValue 160 -#define iOffExpoMask 176 -#define sHalf 192 -#define sSign 208 -#define sTopMask12 224 -#define TinyRange 240 -#define sLn2 256 +/* Offsets for data table __svml_satanh_data_internal_avx512. Ordered + by use in the function. On cold-starts this might help the + prefetcher. Possibly a better idea is to interleave start/end so + that the prefetcher is less likely to detect a stream and pull + irrelivant lines into cache. */ +#define sOne 0 +#define SgnMask 16 +#define sTopMask12 32 +#define iBrkValue 48 +#define iOffExpoMask 64 +#define sPoly 80 +#define sLn2 208 +#define TinyRange 224 #include +#define ATANHF_DATA(x) ((x)+__svml_satanh_data_internal) .section .text.sse4, "ax", @progbits ENTRY(_ZGVbN4v_atanhf_sse4) - subq $72, %rsp - cfi_def_cfa_offset(80) movaps %xmm0, %xmm5 /* Load constants including One = 1 */ - movups sOne+__svml_satanh_data_internal(%rip), %xmm4 + movups ATANHF_DATA(sOne)(%rip), %xmm4 movaps %xmm5, %xmm3 /* Strip off the sign, so treat X as positive until right at the end */ - movups SgnMask+__svml_satanh_data_internal(%rip), %xmm7 - movaps %xmm4, %xmm8 - andps %xmm5, %xmm7 + movups ATANHF_DATA(SgnMask)(%rip), %xmm1 + movaps %xmm4, %xmm2 + andps %xmm1, %xmm0 movaps %xmm4, %xmm10 - movups sTopMask12+__svml_satanh_data_internal(%rip), %xmm11 + movups ATANHF_DATA(sTopMask12)(%rip), %xmm11 movaps %xmm4, %xmm14 movaps %xmm11, %xmm9 + /* * Compute V = 2 * X trivially, and UHi + U_lo = 1 - X in two pieces, * the upper part UHi being <= 12 bits long. Then we have * atanh(X) = 1/2 * log((1 + X) / (1 - X)) = 1/2 * log1p(V / (UHi + ULo)). */ - movaps %xmm7, %xmm12 + movaps %xmm0, %xmm6 + mulps %xmm5, %xmm3 + subps %xmm0, %xmm2 + addps %xmm0, %xmm6 + subps %xmm2, %xmm10 + addps %xmm5, %xmm3 + subps %xmm0, %xmm10 + andps %xmm2, %xmm9 + /* * Check whether |X| < 1, in which case we use the main function. * Otherwise set the rangemask so that the callout will get used. * Note that this will also use the callout for NaNs since not(NaN < 1). */ - movaps %xmm7, %xmm6 - movaps %xmm7, %xmm2 - cmpnltps %xmm4, %xmm6 - cmpltps TinyRange+__svml_satanh_data_internal(%rip), %xmm2 - mulps %xmm5, %xmm3 - subps %xmm7, %xmm8 - addps %xmm7, %xmm12 - movmskps %xmm6, %edx - subps %xmm8, %xmm10 - addps %xmm5, %xmm3 - subps %xmm7, %xmm10 - andps %xmm8, %xmm9 + rcpps %xmm9, %xmm7 + subps %xmm9, %xmm2 + andps %xmm11, %xmm7 - /* - * Now we feed into the log1p code, using H in place of _VARG1 and - * later incorporating L into the reduced argument. - * compute 1+x as high, low parts - */ - movaps %xmm4, %xmm7 - - /* - * Now compute R = 1/(UHi+ULo) * (1 - E) and the error term E - * The first FMR is exact (we force R to 12 bits just in case it - * isn't already, to make absolutely sure), and since E is ~ 2^-12, - * the rounding error in the other one is acceptable. - */ - rcpps %xmm9, %xmm15 - subps %xmm9, %xmm8 - andps %xmm11, %xmm15 /* * Split V as well into upper 12 bits and lower part, so that we can get * a preliminary quotient estimate without rounding error. */ - andps %xmm12, %xmm11 - mulps %xmm15, %xmm9 - addps %xmm8, %xmm10 - subps %xmm11, %xmm12 + andps %xmm6, %xmm11 + mulps %xmm7, %xmm9 + addps %xmm2, %xmm10 + subps %xmm11, %xmm6 /* Hence get initial quotient estimate QHi + QLo = R * VHi + R * VLo */ - mulps %xmm15, %xmm11 - mulps %xmm15, %xmm10 + mulps %xmm7, %xmm11 + mulps %xmm7, %xmm10 subps %xmm9, %xmm14 - mulps %xmm12, %xmm15 + mulps %xmm6, %xmm7 subps %xmm10, %xmm14 /* Compute D = E + E^2 */ @@ -127,8 +111,8 @@ ENTRY(_ZGVbN4v_atanhf_sse4) movaps %xmm4, %xmm8 mulps %xmm14, %xmm13 - /* reduction: compute r, n */ - movdqu iBrkValue+__svml_satanh_data_internal(%rip), %xmm9 + /* reduction: compute r,n */ + movdqu ATANHF_DATA(iBrkValue)(%rip), %xmm9 addps %xmm13, %xmm14 /* @@ -136,168 +120,149 @@ ENTRY(_ZGVbN4v_atanhf_sse4) * = R * (VHi + VLo) * (1 + D) * = QHi + (QHi * D + QLo + QLo * D) */ - movaps %xmm14, %xmm0 - mulps %xmm15, %xmm14 - mulps %xmm11, %xmm0 - addps %xmm14, %xmm15 - movdqu iOffExpoMask+__svml_satanh_data_internal(%rip), %xmm12 + movaps %xmm14, %xmm2 + mulps %xmm7, %xmm14 + mulps %xmm11, %xmm2 + addps %xmm14, %xmm7 + movdqu ATANHF_DATA(iOffExpoMask)(%rip), %xmm12 movaps %xmm4, %xmm14 /* Record the sign for eventual reincorporation. */ - movups sSign+__svml_satanh_data_internal(%rip), %xmm1 - addps %xmm15, %xmm0 + addps %xmm7, %xmm2 + /* * Now finally accumulate the high and low parts of the * argument to log1p, H + L, with a final compensated summation. */ - movaps %xmm0, %xmm6 - andps %xmm5, %xmm1 - + movaps %xmm2, %xmm6 + andnps %xmm5, %xmm1 + movaps %xmm4, %xmm7 /* Or the sign bit in with the tiny result to handle atanh(-0) correctly */ - orps %xmm1, %xmm3 addps %xmm11, %xmm6 maxps %xmm6, %xmm7 minps %xmm6, %xmm8 subps %xmm6, %xmm11 movaps %xmm7, %xmm10 - andps %xmm2, %xmm3 addps %xmm8, %xmm10 - addps %xmm11, %xmm0 + addps %xmm11, %xmm2 subps %xmm10, %xmm7 psubd %xmm9, %xmm10 - addps %xmm7, %xmm8 + addps %xmm8, %xmm7 pand %xmm10, %xmm12 psrad $23, %xmm10 cvtdq2ps %xmm10, %xmm13 - addps %xmm8, %xmm0 + addps %xmm7, %xmm2 /* final reconstruction */ - mulps sLn2+__svml_satanh_data_internal(%rip), %xmm13 pslld $23, %xmm10 paddd %xmm9, %xmm12 psubd %xmm10, %xmm14 /* polynomial evaluation */ subps %xmm4, %xmm12 - mulps %xmm0, %xmm14 - movups sPoly+112+__svml_satanh_data_internal(%rip), %xmm0 - addps %xmm12, %xmm14 - mulps %xmm14, %xmm0 + mulps %xmm14, %xmm2 + movups ATANHF_DATA(sPoly+0)(%rip), %xmm7 + addps %xmm12, %xmm2 + mulps %xmm2, %xmm7 + /* Finally, halve the result and reincorporate the sign */ - movups sHalf+__svml_satanh_data_internal(%rip), %xmm4 - pxor %xmm1, %xmm4 - addps sPoly+96+__svml_satanh_data_internal(%rip), %xmm0 - mulps %xmm14, %xmm0 - addps sPoly+80+__svml_satanh_data_internal(%rip), %xmm0 - mulps %xmm14, %xmm0 - addps sPoly+64+__svml_satanh_data_internal(%rip), %xmm0 - mulps %xmm14, %xmm0 - addps sPoly+48+__svml_satanh_data_internal(%rip), %xmm0 - mulps %xmm14, %xmm0 - addps sPoly+32+__svml_satanh_data_internal(%rip), %xmm0 - mulps %xmm14, %xmm0 - addps sPoly+16+__svml_satanh_data_internal(%rip), %xmm0 - mulps %xmm14, %xmm0 - addps sPoly+__svml_satanh_data_internal(%rip), %xmm0 - mulps %xmm14, %xmm0 - mulps %xmm14, %xmm0 - addps %xmm0, %xmm14 - movaps %xmm2, %xmm0 - addps %xmm13, %xmm14 - mulps %xmm14, %xmm4 - andnps %xmm4, %xmm0 - orps %xmm3, %xmm0 - testl %edx, %edx + addps ATANHF_DATA(sPoly+16)(%rip), %xmm7 + mulps %xmm2, %xmm7 + addps ATANHF_DATA(sPoly+32)(%rip), %xmm7 + mulps %xmm2, %xmm7 + addps ATANHF_DATA(sPoly+48)(%rip), %xmm7 + mulps %xmm2, %xmm7 + addps ATANHF_DATA(sPoly+64)(%rip), %xmm7 + mulps %xmm2, %xmm7 + addps ATANHF_DATA(sPoly+80)(%rip), %xmm7 + mulps %xmm2, %xmm7 + addps ATANHF_DATA(sPoly+96)(%rip), %xmm7 + mulps %xmm2, %xmm7 + movaps ATANHF_DATA(sPoly+112)(%rip), %xmm6 + addps %xmm6, %xmm7 + mulps %xmm2, %xmm7 + mulps %xmm2, %xmm7 + mulps ATANHF_DATA(sLn2)(%rip), %xmm13 + /* We can build `sHalf` with `sPoly & sOne`. */ + andps %xmm4, %xmm6 + orps %xmm1, %xmm3 + xorps %xmm6, %xmm1 - /* Go to special inputs processing branch */ - jne L(SPECIAL_VALUES_BRANCH) - # LOE rbx rbp r12 r13 r14 r15 edx xmm0 xmm5 + addps %xmm2, %xmm7 + addps %xmm13, %xmm7 + mulps %xmm7, %xmm1 - /* Restore registers - * and exit the function - */ + /* Finish check of NaNs. */ + cmpleps %xmm0, %xmm4 + movmskps %xmm4, %edx + cmpltps ATANHF_DATA(TinyRange)(%rip), %xmm0 -L(EXIT): - addq $72, %rsp - cfi_def_cfa_offset(8) + andps %xmm0, %xmm3 + andnps %xmm1, %xmm0 + orps %xmm3, %xmm0 + + testl %edx, %edx + /* Go to special inputs processing branch. */ + jne L(SPECIAL_VALUES_BRANCH) + # LOE rbx rbp r12 r13 r14 r15 xmm0 + /* No registers to restore on fast path. */ ret - cfi_def_cfa_offset(80) - /* Branch to process - * special inputs - */ + /* Cold case. edx has 1s where there was a special value that + needs to be handled by a atanhf call. Optimize for code size + more so than speed here. */ L(SPECIAL_VALUES_BRANCH): - movups %xmm5, 32(%rsp) - movups %xmm0, 48(%rsp) - # LOE rbx rbp r12 r13 r14 r15 edx - - xorl %eax, %eax - movq %r12, 16(%rsp) - cfi_offset(12, -64) - movl %eax, %r12d - movq %r13, 8(%rsp) - cfi_offset(13, -72) - movl %edx, %r13d - movq %r14, (%rsp) - cfi_offset(14, -80) - # LOE rbx rbp r15 r12d r13d - - /* Range mask - * bits check - */ - -L(RANGEMASK_CHECK): - btl %r12d, %r13d - - /* Call scalar math function */ - jc L(SCALAR_MATH_CALL) - # LOE rbx rbp r15 r12d r13d - - /* Special inputs - * processing loop - */ - + # LOE rbx rdx rbp r12 r13 r14 r15 xmm0 xmm5 + /* Stack coming in 16-byte aligned. Set 8-byte misaligned so on + call entry will be 16-byte aligned. */ + subq $56, %rsp + cfi_def_cfa_offset(64) + movups %xmm0, 24(%rsp) + movups %xmm5, 40(%rsp) + + /* Use rbx/rbp for callee save registers as they get short + encoding for many instructions (as compared with r12/r13). */ + movq %rbx, (%rsp) + cfi_offset(rbx, -64) + movq %rbp, 8(%rsp) + cfi_offset(rbp, -56) + /* edx has 1s where there was a special value that needs to be handled + by a tanhf call. */ + movl %edx, %ebx L(SPECIAL_VALUES_LOOP): - incl %r12d - cmpl $4, %r12d - - /* Check bits in range mask */ - jl L(RANGEMASK_CHECK) - # LOE rbx rbp r15 r12d r13d - - movq 16(%rsp), %r12 - cfi_restore(12) - movq 8(%rsp), %r13 - cfi_restore(13) - movq (%rsp), %r14 - cfi_restore(14) - movups 48(%rsp), %xmm0 - - /* Go to exit */ - jmp L(EXIT) - cfi_offset(12, -64) - cfi_offset(13, -72) - cfi_offset(14, -80) - # LOE rbx rbp r12 r13 r14 r15 xmm0 - - /* Scalar math fucntion call - * to process special input - */ - -L(SCALAR_MATH_CALL): - movl %r12d, %r14d - movss 32(%rsp, %r14, 4), %xmm0 + # LOE rbx rbp r12 r13 r14 r15 + /* use rbp as index for special value that is saved across calls to + tanhf. We technically don't need a callee save register here as offset + to rsp is always [0, 12] so we can restore rsp by realigning to 64. + Essentially the tradeoff is 1 extra save/restore vs 2 extra instructions + in the loop. */ + xorl %ebp, %ebp + bsfl %ebx, %ebp + + /* Scalar math fucntion call to process special input. */ + movss 40(%rsp, %rbp, 4), %xmm0 call atanhf@PLT - # LOE rbx rbp r14 r15 r12d r13d xmm0 - - movss %xmm0, 48(%rsp, %r14, 4) - - /* Process special inputs in loop */ - jmp L(SPECIAL_VALUES_LOOP) - # LOE rbx rbp r15 r12d r13d + /* No good way to avoid the store-forwarding fault this will cause on + return. `lfence` avoids the SF fault but at greater cost as it + serialized stack/callee save restoration. */ + movss %xmm0, 24(%rsp, %rbp, 4) + + leal -1(%rbx), %eax + andl %eax, %ebx + jnz L(SPECIAL_VALUES_LOOP) + # LOE r12 r13 r14 r15 + /* All results have been written to 24(%rsp). */ + movups 24(%rsp), %xmm0 + movq (%rsp), %rbx + cfi_restore(rbx) + movq 8(%rsp), %rbp + cfi_restore(rbp) + addq $56, %rsp + cfi_def_cfa_offset(8) + ret END(_ZGVbN4v_atanhf_sse4) .section .rodata, "a" @@ -305,56 +270,51 @@ END(_ZGVbN4v_atanhf_sse4) #ifdef __svml_satanh_data_internal_typedef typedef unsigned int VUINT32; -typedef struct { - __declspec(align(16)) VUINT32 SgnMask[4][1]; +typedef struct{ __declspec(align(16)) VUINT32 sOne[4][1]; - __declspec(align(16)) VUINT32 sPoly[8][4][1]; + __declspec(align(16)) VUINT32 SgnMask[4][1]; + __declspec(align(16)) VUINT32 sTopMask12[4][1]; __declspec(align(16)) VUINT32 iBrkValue[4][1]; __declspec(align(16)) VUINT32 iOffExpoMask[4][1]; - __declspec(align(16)) VUINT32 sHalf[4][1]; - __declspec(align(16)) VUINT32 sSign[4][1]; - __declspec(align(16)) VUINT32 sTopMask12[4][1]; - __declspec(align(16)) VUINT32 TinyRange[4][1]; + __declspec(align(16)) VUINT32 sPoly[8][4][1]; __declspec(align(16)) VUINT32 sLn2[4][1]; + __declspec(align(16)) VUINT32 TinyRange[4][1]; } __svml_satanh_data_internal; #endif + __svml_satanh_data_internal: - /* SgnMask */ - .long 0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff /* sOne = SP 1.0 */ .align 16 .long 0x3f800000, 0x3f800000, 0x3f800000, 0x3f800000 - /* sPoly[] = SP polynomial */ + /* SgnMask */ + .long 0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff + /* sTopMask12 */ .align 16 - .long 0xbf000000, 0xbf000000, 0xbf000000, 0xbf000000 /* -5.0000000000000000000000000e-01 P0 */ - .long 0x3eaaaa94, 0x3eaaaa94, 0x3eaaaa94, 0x3eaaaa94 /* 3.3333265781402587890625000e-01 P1 */ - .long 0xbe80058e, 0xbe80058e, 0xbe80058e, 0xbe80058e /* -2.5004237890243530273437500e-01 P2 */ - .long 0x3e4ce190, 0x3e4ce190, 0x3e4ce190, 0x3e4ce190 /* 2.0007920265197753906250000e-01 P3 */ - .long 0xbe28ad37, 0xbe28ad37, 0xbe28ad37, 0xbe28ad37 /* -1.6472326219081878662109375e-01 P4 */ - .long 0x3e0fcb12, 0x3e0fcb12, 0x3e0fcb12, 0x3e0fcb12 /* 1.4042308926582336425781250e-01 P5 */ - .long 0xbe1ad9e3, 0xbe1ad9e3, 0xbe1ad9e3, 0xbe1ad9e3 /* -1.5122179687023162841796875e-01 P6 */ - .long 0x3e0d84ed, 0x3e0d84ed, 0x3e0d84ed, 0x3e0d84ed /* 1.3820238411426544189453125e-01 P7 */ + .long 0xFFFFF000, 0xFFFFF000, 0xFFFFF000, 0xFFFFF000 /* iBrkValue = SP 2/3 */ .align 16 .long 0x3f2aaaab, 0x3f2aaaab, 0x3f2aaaab, 0x3f2aaaab - /* iOffExpoMask = SP significand mask */ + /* iOffExpoMask = SP significand mask ==*/ .align 16 .long 0x007fffff, 0x007fffff, 0x007fffff, 0x007fffff - /* sHalf */ - .align 16 - .long 0x3F000000, 0x3F000000, 0x3F000000, 0x3F000000 - /* sSign */ + + /* sPoly[] = SP polynomial */ .align 16 - .long 0x80000000, 0x80000000, 0x80000000, 0x80000000 - /* sTopMask12 */ + .long 0x3e0d84ed, 0x3e0d84ed, 0x3e0d84ed, 0x3e0d84ed /* 1.3820238411426544189453125e-01 P7 */ + .long 0xbe1ad9e3, 0xbe1ad9e3, 0xbe1ad9e3, 0xbe1ad9e3 /* -1.5122179687023162841796875e-01 P6 */ + .long 0x3e0fcb12, 0x3e0fcb12, 0x3e0fcb12, 0x3e0fcb12 /* 1.4042308926582336425781250e-01 P5 */ + .long 0xbe28ad37, 0xbe28ad37, 0xbe28ad37, 0xbe28ad37 /* -1.6472326219081878662109375e-01 P4 */ + .long 0x3e4ce190, 0x3e4ce190, 0x3e4ce190, 0x3e4ce190 /* 2.0007920265197753906250000e-01 P3 */ + .long 0xbe80058e, 0xbe80058e, 0xbe80058e, 0xbe80058e /* -2.5004237890243530273437500e-01 P2 */ + .long 0x3eaaaa94, 0x3eaaaa94, 0x3eaaaa94, 0x3eaaaa94 /* 3.3333265781402587890625000e-01 P1 */ + .long 0xbf000000, 0xbf000000, 0xbf000000, 0xbf000000 /* -5.0000000000000000000000000e-01 P0 */ + + /* sLn2 = SP ln(2) */ .align 16 - .long 0xFFFFF000, 0xFFFFF000, 0xFFFFF000, 0xFFFFF000 + .long 0x3f317218, 0x3f317218, 0x3f317218, 0x3f317218 /* TinyRange */ .align 16 .long 0x0C000000, 0x0C000000, 0x0C000000, 0x0C000000 - /* sLn2 = SP ln(2) */ - .align 16 - .long 0x3f317218, 0x3f317218, 0x3f317218, 0x3f317218 .align 16 .type __svml_satanh_data_internal, @object .size __svml_satanh_data_internal, .-__svml_satanh_data_internal