Message ID | 20220609165835.2527760-3-goldstein.w.n@gmail.com |
---|---|
State | New |
Headers | show |
Series | [v3,1/7] x86: Improve svml_s_atanhf16_core_avx512.S | expand |
On Thu, Jun 9, 2022 at 9:58 AM Noah Goldstein <goldstein.w.n@gmail.com> wrote: > > 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 > --- > .../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 <sysdep.h> > +#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 > -- > 2.34.1 > LGTM. Thanks.
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 <sysdep.h> +#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