| .file "expf.s" |
| |
| |
| // Copyright (c) 2000 - 2005, Intel Corporation |
| // All rights reserved. |
| // |
| // Contributed 2000 by the Intel Numerics Group, Intel Corporation |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // |
| // * Redistributions in binary form must reproduce the above copyright |
| // notice, this list of conditions and the following disclaimer in the |
| // documentation and/or other materials provided with the distribution. |
| // |
| // * The name of Intel Corporation may not be used to endorse or promote |
| // products derived from this software without specific prior written |
| // permission. |
| |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL INTEL OR ITS |
| // CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| // EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| // PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
| // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY |
| // OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY OR TORT (INCLUDING |
| // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
| // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| // |
| // Intel Corporation is the author of this code, and requests that all |
| // problem reports or change requests be submitted to it directly at |
| // http://www.intel.com/software/products/opensource/libraries/num.htm. |
| |
| // History |
| //********************************************************************* |
| // 02/02/00 Original version |
| // 04/04/00 Unwind support added |
| // 08/15/00 Bundle added after call to __libm_error_support to properly |
| // set [the previously overwritten] GR_Parameter_RESULT. |
| // 08/21/00 Improvements to save 2 cycles on main path, and shorten x=0 case |
| // 12/07/00 Widen main path, shorten x=inf, nan paths |
| // 03/15/01 Fix monotonicity problem around x=0 for round to +inf |
| // 02/05/02 Corrected uninitialize predicate in POSSIBLE_UNDERFLOW path |
| // 05/20/02 Cleaned up namespace and sf0 syntax |
| // 07/26/02 Algorithm changed, accuracy improved |
| // 09/26/02 support of higher precision inputs added, underflow threshold |
| // corrected |
| // 11/15/02 Improved performance on Itanium 2, added possible over/under paths |
| // 05/30/03 Set inexact flag on unmasked overflow/underflow |
| // 03/31/05 Reformatted delimiters between data tables |
| // |
| // |
| // API |
| //********************************************************************* |
| // float expf(float) |
| // |
| // Overview of operation |
| //********************************************************************* |
| // Take the input x. w is "how many log2/128 in x?" |
| // w = x * 64/log2 |
| // NJ = int(w) |
| // x = NJ*log2/64 + R |
| |
| // NJ = 64*n + j |
| // x = n*log2 + (log2/64)*j + R |
| // |
| // So, exp(x) = 2^n * 2^(j/64)* exp(R) |
| // |
| // T = 2^n * 2^(j/64) |
| // Construct 2^n |
| // Get 2^(j/64) table |
| // actually all the entries of 2^(j/64) table are stored in DP and |
| // with exponent bits set to 0 -> multiplication on 2^n can be |
| // performed by doing logical "or" operation with bits presenting 2^n |
| |
| // exp(R) = 1 + (exp(R) - 1) |
| // P = exp(R) - 1 approximated by Taylor series of 3rd degree |
| // P = A3*R^3 + A2*R^2 + R, A3 = 1/6, A2 = 1/2 |
| // |
| |
| // The final result is reconstructed as follows |
| // exp(x) = T + T*P |
| |
| // Special values |
| //********************************************************************* |
| // expf(+0) = 1.0 |
| // expf(-0) = 1.0 |
| |
| // expf(+qnan) = +qnan |
| // expf(-qnan) = -qnan |
| // expf(+snan) = +qnan |
| // expf(-snan) = -qnan |
| |
| // expf(-inf) = +0 |
| // expf(+inf) = +inf |
| |
| // Overflow and Underflow |
| //********************************************************************* |
| // expf(x) = largest single normal when |
| // x = 88.72283 = 0x42b17217 |
| |
| // expf(x) = smallest single normal when |
| // x = -87.33654 = 0xc2aeac4f |
| |
| // expf(x) = largest round-to-nearest single zero when |
| // x = -103.97208 = 0xc2cff1b5 |
| |
| |
| // Registers used |
| //********************************************************************* |
| // Floating Point registers used: |
| // f8, input |
| // f6,f7, f9 -> f15, f32 -> f40 |
| |
| // General registers used: |
| // r3, r23 -> r38 |
| |
| // Predicate registers used: |
| // p10 -> p15 |
| |
| // Assembly macros |
| //********************************************************************* |
| // integer registers used |
| // scratch |
| rNJ = r3 |
| |
| rTmp = r23 |
| rJ = r23 |
| rN = r24 |
| rTblAddr = r25 |
| rA3 = r26 |
| rExpHalf = r27 |
| rLn2Div64 = r28 |
| r17ones_m1 = r29 |
| rGt_ln = r29 |
| rRightShifter = r30 |
| r64DivLn2 = r31 |
| // stacked |
| GR_SAVE_PFS = r32 |
| GR_SAVE_B0 = r33 |
| GR_SAVE_GP = r34 |
| GR_Parameter_X = r35 |
| GR_Parameter_Y = r36 |
| GR_Parameter_RESULT = r37 |
| GR_Parameter_TAG = r38 |
| |
| // floating point registers used |
| FR_X = f10 |
| FR_Y = f1 |
| FR_RESULT = f8 |
| // scratch |
| fRightShifter = f6 |
| f64DivLn2 = f7 |
| fNormX = f9 |
| fNint = f10 |
| fN = f11 |
| fR = f12 |
| fLn2Div64 = f13 |
| fA2 = f14 |
| fA3 = f15 |
| // stacked |
| fP = f32 |
| fT = f33 |
| fMIN_SGL_OFLOW_ARG = f34 |
| fMAX_SGL_ZERO_ARG = f35 |
| fMAX_SGL_NORM_ARG = f36 |
| fMIN_SGL_NORM_ARG = f37 |
| fRSqr = f38 |
| fTmp = f39 |
| fGt_pln = f39 |
| fWre_urm_f8 = f40 |
| fFtz_urm_f8 = f40 |
| |
| |
| RODATA |
| .align 16 |
| |
| LOCAL_OBJECT_START(_expf_table) |
| data4 0x42b17218 // Smallest sgl arg to overflow sgl result, +88.7228 |
| data4 0xc2cff1b5 // Largest sgl for rnd-to-nearest 0 result, -103.9720 |
| data4 0x42b17217 // Largest sgl arg to give normal sgl result, +88.7228 |
| data4 0xc2aeac4f // Smallest sgl arg to give normal sgl result, -87.3365 |
| // |
| // 2^(j/64) table, j goes from 0 to 63 |
| data8 0x0000000000000000 // 2^(0/64) |
| data8 0x00002C9A3E778061 // 2^(1/64) |
| data8 0x000059B0D3158574 // 2^(2/64) |
| data8 0x0000874518759BC8 // 2^(3/64) |
| data8 0x0000B5586CF9890F // 2^(4/64) |
| data8 0x0000E3EC32D3D1A2 // 2^(5/64) |
| data8 0x00011301D0125B51 // 2^(6/64) |
| data8 0x0001429AAEA92DE0 // 2^(7/64) |
| data8 0x000172B83C7D517B // 2^(8/64) |
| data8 0x0001A35BEB6FCB75 // 2^(9/64) |
| data8 0x0001D4873168B9AA // 2^(10/64) |
| data8 0x0002063B88628CD6 // 2^(11/64) |
| data8 0x0002387A6E756238 // 2^(12/64) |
| data8 0x00026B4565E27CDD // 2^(13/64) |
| data8 0x00029E9DF51FDEE1 // 2^(14/64) |
| data8 0x0002D285A6E4030B // 2^(15/64) |
| data8 0x000306FE0A31B715 // 2^(16/64) |
| data8 0x00033C08B26416FF // 2^(17/64) |
| data8 0x000371A7373AA9CB // 2^(18/64) |
| data8 0x0003A7DB34E59FF7 // 2^(19/64) |
| data8 0x0003DEA64C123422 // 2^(20/64) |
| data8 0x0004160A21F72E2A // 2^(21/64) |
| data8 0x00044E086061892D // 2^(22/64) |
| data8 0x000486A2B5C13CD0 // 2^(23/64) |
| data8 0x0004BFDAD5362A27 // 2^(24/64) |
| data8 0x0004F9B2769D2CA7 // 2^(25/64) |
| data8 0x0005342B569D4F82 // 2^(26/64) |
| data8 0x00056F4736B527DA // 2^(27/64) |
| data8 0x0005AB07DD485429 // 2^(28/64) |
| data8 0x0005E76F15AD2148 // 2^(29/64) |
| data8 0x0006247EB03A5585 // 2^(30/64) |
| data8 0x0006623882552225 // 2^(31/64) |
| data8 0x0006A09E667F3BCD // 2^(32/64) |
| data8 0x0006DFB23C651A2F // 2^(33/64) |
| data8 0x00071F75E8EC5F74 // 2^(34/64) |
| data8 0x00075FEB564267C9 // 2^(35/64) |
| data8 0x0007A11473EB0187 // 2^(36/64) |
| data8 0x0007E2F336CF4E62 // 2^(37/64) |
| data8 0x00082589994CCE13 // 2^(38/64) |
| data8 0x000868D99B4492ED // 2^(39/64) |
| data8 0x0008ACE5422AA0DB // 2^(40/64) |
| data8 0x0008F1AE99157736 // 2^(41/64) |
| data8 0x00093737B0CDC5E5 // 2^(42/64) |
| data8 0x00097D829FDE4E50 // 2^(43/64) |
| data8 0x0009C49182A3F090 // 2^(44/64) |
| data8 0x000A0C667B5DE565 // 2^(45/64) |
| data8 0x000A5503B23E255D // 2^(46/64) |
| data8 0x000A9E6B5579FDBF // 2^(47/64) |
| data8 0x000AE89F995AD3AD // 2^(48/64) |
| data8 0x000B33A2B84F15FB // 2^(49/64) |
| data8 0x000B7F76F2FB5E47 // 2^(50/64) |
| data8 0x000BCC1E904BC1D2 // 2^(51/64) |
| data8 0x000C199BDD85529C // 2^(52/64) |
| data8 0x000C67F12E57D14B // 2^(53/64) |
| data8 0x000CB720DCEF9069 // 2^(54/64) |
| data8 0x000D072D4A07897C // 2^(55/64) |
| data8 0x000D5818DCFBA487 // 2^(56/64) |
| data8 0x000DA9E603DB3285 // 2^(57/64) |
| data8 0x000DFC97337B9B5F // 2^(58/64) |
| data8 0x000E502EE78B3FF6 // 2^(59/64) |
| data8 0x000EA4AFA2A490DA // 2^(60/64) |
| data8 0x000EFA1BEE615A27 // 2^(61/64) |
| data8 0x000F50765B6E4540 // 2^(62/64) |
| data8 0x000FA7C1819E90D8 // 2^(63/64) |
| LOCAL_OBJECT_END(_expf_table) |
| |
| |
| .section .text |
| GLOBAL_IEEE754_ENTRY(expf) |
| |
| { .mlx |
| addl rTblAddr = @ltoff(_expf_table),gp |
| movl r64DivLn2 = 0x40571547652B82FE // 64/ln(2) |
| } |
| { .mlx |
| addl rA3 = 0x3E2AA, r0 // high bits of 1.0/6.0 rounded to SP |
| movl rRightShifter = 0x43E8000000000000 // DP Right Shifter |
| } |
| ;; |
| |
| { .mfi |
| // point to the beginning of the table |
| ld8 rTblAddr = [rTblAddr] |
| fclass.m p14, p0 = f8, 0x22 // test for -INF |
| shl rA3 = rA3, 12 // 0x3E2AA000, approx to 1.0/6.0 in SP |
| } |
| { .mfi |
| nop.m 0 |
| fnorm.s1 fNormX = f8 // normalized x |
| addl rExpHalf = 0xFFFE, r0 // exponent of 1/2 |
| } |
| ;; |
| |
| { .mfi |
| setf.d f64DivLn2 = r64DivLn2 // load 64/ln(2) to FP reg |
| fclass.m p15, p0 = f8, 0x1e1 // test for NaT,NaN,+Inf |
| nop.i 0 |
| } |
| { .mlx |
| // load Right Shifter to FP reg |
| setf.d fRightShifter = rRightShifter |
| movl rLn2Div64 = 0x3F862E42FEFA39EF // DP ln(2)/64 in GR |
| } |
| ;; |
| |
| { .mfi |
| nop.m 0 |
| fcmp.eq.s1 p13, p0 = f0, f8 // test for x = 0.0 |
| nop.i 0 |
| } |
| { .mfb |
| setf.s fA3 = rA3 // load A3 to FP reg |
| (p14) fma.s.s0 f8 = f0, f1, f0 // result if x = -inf |
| (p14) br.ret.spnt b0 // exit here if x = -inf |
| } |
| ;; |
| |
| { .mfi |
| setf.exp fA2 = rExpHalf // load A2 to FP reg |
| fcmp.eq.s0 p6, p0 = f8, f0 // Dummy to flag denorm |
| nop.i 0 |
| } |
| { .mfb |
| setf.d fLn2Div64 = rLn2Div64 // load ln(2)/64 to FP reg |
| (p15) fma.s.s0 f8 = f8, f1, f0 // result if x = NaT,NaN,+Inf |
| (p15) br.ret.spnt b0 // exit here if x = NaT,NaN,+Inf |
| } |
| ;; |
| |
| { .mfb |
| // overflow and underflow_zero threshold |
| ldfps fMIN_SGL_OFLOW_ARG, fMAX_SGL_ZERO_ARG = [rTblAddr], 8 |
| (p13) fma.s.s0 f8 = f1, f1, f0 // result if x = 0.0 |
| (p13) br.ret.spnt b0 // exit here if x =0.0 |
| } |
| ;; |
| |
| // max normal and underflow_denorm threshold |
| { .mfi |
| ldfps fMAX_SGL_NORM_ARG, fMIN_SGL_NORM_ARG = [rTblAddr], 8 |
| nop.f 0 |
| nop.i 0 |
| } |
| ;; |
| |
| { .mfi |
| nop.m 0 |
| // x*(64/ln(2)) + Right Shifter |
| fma.s1 fNint = fNormX, f64DivLn2, fRightShifter |
| nop.i 0 |
| } |
| ;; |
| |
| // Divide arguments into the following categories: |
| // Certain Underflow p11 - -inf < x <= MAX_SGL_ZERO_ARG |
| // Possible Underflow p13 - MAX_SGL_ZERO_ARG < x < MIN_SGL_NORM_ARG |
| // Certain Safe - MIN_SGL_NORM_ARG <= x <= MAX_SGL_NORM_ARG |
| // Possible Overflow p14 - MAX_SGL_NORM_ARG < x < MIN_SGL_OFLOW_ARG |
| // Certain Overflow p15 - MIN_SGL_OFLOW_ARG <= x < +inf |
| // |
| // If the input is really a single arg, then there will never be |
| // "Possible Overflow" arguments. |
| // |
| |
| { .mfi |
| nop.m 0 |
| // check for overflow |
| fcmp.ge.s1 p15, p0 = fNormX, fMIN_SGL_OFLOW_ARG |
| nop.i 0 |
| } |
| ;; |
| |
| { .mfi |
| nop.m 0 |
| // check for underflow and tiny (+0) result |
| fcmp.le.s1 p11, p0 = fNormX, fMAX_SGL_ZERO_ARG |
| nop.i 0 |
| } |
| { .mfb |
| nop.m 0 |
| fms.s1 fN = fNint, f1, fRightShifter // n in FP register |
| // branch out if overflow |
| (p15) br.cond.spnt EXP_CERTAIN_OVERFLOW |
| } |
| ;; |
| |
| { .mfb |
| getf.sig rNJ = fNint // bits of n, j |
| // check for underflow and deno result |
| fcmp.lt.s1 p13, p0 = fNormX, fMIN_SGL_NORM_ARG |
| // branch out if underflow and tiny (+0) result |
| (p11) br.cond.spnt EXP_CERTAIN_UNDERFLOW |
| } |
| ;; |
| |
| { .mfi |
| nop.m 0 |
| // check for possible overflow |
| fcmp.gt.s1 p14, p0 = fNormX, fMAX_SGL_NORM_ARG |
| extr.u rJ = rNJ, 0, 6 // bits of j |
| } |
| { .mfi |
| addl rN = 0xFFFF - 63, rNJ // biased and shifted n |
| fnma.s1 fR = fLn2Div64, fN, fNormX // R = x - N*ln(2)/64 |
| nop.i 0 |
| } |
| ;; |
| |
| { .mfi |
| shladd rJ = rJ, 3, rTblAddr // address in the 2^(j/64) table |
| nop.f 0 |
| shr rN = rN, 6 // biased n |
| } |
| ;; |
| |
| { .mfi |
| ld8 rJ = [rJ] |
| nop.f 0 |
| shl rN = rN, 52 // 2^n bits in DP format |
| } |
| ;; |
| |
| { .mfi |
| or rN = rN, rJ // bits of 2^n * 2^(j/64) in DP format |
| nop.f 0 |
| nop.i 0 |
| } |
| ;; |
| |
| { .mfi |
| setf.d fT = rN // 2^n * 2^(j/64) |
| fma.s1 fP = fA3, fR, fA2 // A3*R + A2 |
| nop.i 0 |
| } |
| { .mfi |
| nop.m 0 |
| fma.s1 fRSqr = fR, fR, f0 // R^2 |
| nop.i 0 |
| } |
| ;; |
| |
| { .mfi |
| nop.m 0 |
| fma.s1 fP = fP, fRSqr, fR // P = (A3*R + A2)*R^2 + R |
| nop.i 0 |
| } |
| ;; |
| |
| { .mbb |
| nop.m 0 |
| // branch out if possible underflow |
| (p13) br.cond.spnt EXP_POSSIBLE_UNDERFLOW |
| // branch out if possible overflow result |
| (p14) br.cond.spnt EXP_POSSIBLE_OVERFLOW |
| } |
| ;; |
| |
| { .mfb |
| nop.m 0 |
| // final result in the absence of over- and underflow |
| fma.s.s0 f8 = fP, fT, fT |
| // exit here in the absence of over- and underflow |
| br.ret.sptk b0 |
| } |
| ;; |
| |
| EXP_POSSIBLE_OVERFLOW: |
| |
| // Here if fMAX_SGL_NORM_ARG < x < fMIN_SGL_OFLOW_ARG |
| // This cannot happen if input is a single, only if input higher precision. |
| // Overflow is a possibility, not a certainty. |
| |
| // Recompute result using status field 2 with user's rounding mode, |
| // and wre set. If result is larger than largest single, then we have |
| // overflow |
| |
| { .mfi |
| mov rGt_ln = 0x1007f // Exponent for largest single + 1 ulp |
| fsetc.s2 0x7F,0x42 // Get user's round mode, set wre |
| nop.i 0 |
| } |
| ;; |
| |
| { .mfi |
| setf.exp fGt_pln = rGt_ln // Create largest single + 1 ulp |
| fma.s.s2 fWre_urm_f8 = fP, fT, fT // Result with wre set |
| nop.i 0 |
| } |
| ;; |
| |
| { .mfi |
| nop.m 0 |
| fsetc.s2 0x7F,0x40 // Turn off wre in sf2 |
| nop.i 0 |
| } |
| ;; |
| |
| { .mfi |
| nop.m 0 |
| fcmp.ge.s1 p6, p0 = fWre_urm_f8, fGt_pln // Test for overflow |
| nop.i 0 |
| } |
| ;; |
| |
| { .mfb |
| nop.m 0 |
| nop.f 0 |
| (p6) br.cond.spnt EXP_CERTAIN_OVERFLOW // Branch if overflow |
| } |
| ;; |
| |
| { .mfb |
| nop.m 0 |
| fma.s.s0 f8 = fP, fT, fT |
| br.ret.sptk b0 // Exit if really no overflow |
| } |
| ;; |
| |
| // here if overflow |
| EXP_CERTAIN_OVERFLOW: |
| { .mmi |
| addl r17ones_m1 = 0x1FFFE, r0 |
| ;; |
| setf.exp fTmp = r17ones_m1 |
| nop.i 0 |
| } |
| ;; |
| |
| { .mfi |
| alloc r32=ar.pfs,0,3,4,0 |
| fmerge.s FR_X = f8,f8 |
| nop.i 0 |
| } |
| { .mfb |
| mov GR_Parameter_TAG = 16 |
| fma.s.s0 FR_RESULT = fTmp, fTmp, fTmp // Set I,O and +INF result |
| br.cond.sptk __libm_error_region |
| } |
| ;; |
| |
| EXP_POSSIBLE_UNDERFLOW: |
| |
| // Here if fMAX_SGL_ZERO_ARG < x < fMIN_SGL_NORM_ARG |
| // Underflow is a possibility, not a certainty |
| |
| // We define an underflow when the answer with |
| // ftz set |
| // is zero (tiny numbers become zero) |
| |
| // Notice (from below) that if we have an unlimited exponent range, |
| // then there is an extra machine number E between the largest denormal and |
| // the smallest normal. |
| |
| // So if with unbounded exponent we round to E or below, then we are |
| // tiny and underflow has occurred. |
| |
| // But notice that you can be in a situation where we are tiny, namely |
| // rounded to E, but when the exponent is bounded we round to smallest |
| // normal. So the answer can be the smallest normal with underflow. |
| |
| // E |
| // -----+--------------------+--------------------+----- |
| // | | | |
| // 1.1...10 2^-3fff 1.1...11 2^-3fff 1.0...00 2^-3ffe |
| // 0.1...11 2^-3ffe (biased, 1) |
| // largest dn smallest normal |
| |
| { .mfi |
| nop.m 0 |
| fsetc.s2 0x7F,0x41 // Get user's round mode, set ftz |
| nop.i 0 |
| } |
| ;; |
| |
| { .mfi |
| nop.m 0 |
| fma.s.s2 fFtz_urm_f8 = fP, fT, fT // Result with ftz set |
| nop.i 0 |
| } |
| ;; |
| |
| { .mfi |
| nop.m 0 |
| fsetc.s2 0x7F,0x40 // Turn off ftz in sf2 |
| nop.i 0 |
| } |
| ;; |
| |
| { .mfi |
| nop.m 0 |
| fcmp.eq.s1 p6, p7 = fFtz_urm_f8, f0 // Test for underflow |
| nop.i 0 |
| } |
| { .mfi |
| nop.m 0 |
| fma.s.s0 f8 = fP, fT, fT // Compute result, set I, maybe U |
| nop.i 0 |
| } |
| ;; |
| |
| { .mbb |
| nop.m 0 |
| (p6) br.cond.spnt EXP_UNDERFLOW_COMMON // Branch if really underflow |
| (p7) br.ret.sptk b0 // Exit if really no underflow |
| } |
| ;; |
| |
| EXP_CERTAIN_UNDERFLOW: |
| // Here if x < fMAX_SGL_ZERO_ARG |
| // Result will be zero (or smallest denorm if round to +inf) with I, U set |
| { .mmi |
| mov rTmp = 1 |
| ;; |
| setf.exp fTmp = rTmp // Form small normal |
| nop.i 0 |
| } |
| ;; |
| |
| { .mfi |
| nop.m 0 |
| fmerge.se fTmp = fTmp, f64DivLn2 // Small with non-trial signif |
| nop.i 0 |
| } |
| ;; |
| |
| { .mfb |
| nop.m 0 |
| fma.s.s0 f8 = fTmp, fTmp, f0 // Set I,U, tiny (+0.0) result |
| br.cond.sptk EXP_UNDERFLOW_COMMON |
| } |
| ;; |
| |
| EXP_UNDERFLOW_COMMON: |
| // Determine if underflow result is zero or nonzero |
| { .mfi |
| alloc r32=ar.pfs,0,3,4,0 |
| fcmp.eq.s1 p6, p0 = f8, f0 |
| nop.i 0 |
| } |
| ;; |
| |
| { .mfb |
| nop.m 0 |
| fmerge.s FR_X = fNormX,fNormX |
| (p6) br.cond.spnt EXP_UNDERFLOW_ZERO |
| } |
| ;; |
| |
| EXP_UNDERFLOW_NONZERO: |
| // Here if x < fMIN_SGL_NORM_ARG and result nonzero; |
| // I, U are set |
| { .mfb |
| mov GR_Parameter_TAG = 17 |
| nop.f 0 // FR_RESULT already set |
| br.cond.sptk __libm_error_region |
| } |
| ;; |
| |
| EXP_UNDERFLOW_ZERO: |
| // Here if x < fMIN_SGL_NORM_ARG and result zero; |
| // I, U are set |
| { .mfb |
| mov GR_Parameter_TAG = 17 |
| nop.f 0 // FR_RESULT already set |
| br.cond.sptk __libm_error_region |
| } |
| ;; |
| |
| GLOBAL_IEEE754_END(expf) |
| |
| |
| LOCAL_LIBM_ENTRY(__libm_error_region) |
| .prologue |
| { .mfi |
| add GR_Parameter_Y=-32,sp // Parameter 2 value |
| nop.f 0 |
| .save ar.pfs,GR_SAVE_PFS |
| mov GR_SAVE_PFS=ar.pfs // Save ar.pfs |
| } |
| { .mfi |
| .fframe 64 |
| add sp=-64,sp // Create new stack |
| nop.f 0 |
| mov GR_SAVE_GP=gp // Save gp |
| };; |
| { .mmi |
| stfs [GR_Parameter_Y] = FR_Y,16 // Store Parameter 2 on stack |
| add GR_Parameter_X = 16,sp // Parameter 1 address |
| .save b0, GR_SAVE_B0 |
| mov GR_SAVE_B0=b0 // Save b0 |
| };; |
| .body |
| { .mfi |
| stfs [GR_Parameter_X] = FR_X // Store Parameter 1 on stack |
| nop.f 0 |
| add GR_Parameter_RESULT = 0,GR_Parameter_Y // Parameter 3 address |
| } |
| { .mib |
| stfs [GR_Parameter_Y] = FR_RESULT // Store Parameter 3 on stack |
| add GR_Parameter_Y = -16,GR_Parameter_Y |
| br.call.sptk b0=__libm_error_support# // Call error handling function |
| };; |
| |
| { .mmi |
| add GR_Parameter_RESULT = 48,sp |
| nop.m 0 |
| nop.i 0 |
| };; |
| |
| { .mmi |
| ldfs f8 = [GR_Parameter_RESULT] // Get return result off stack |
| .restore sp |
| add sp = 64,sp // Restore stack pointer |
| mov b0 = GR_SAVE_B0 // Restore return address |
| };; |
| { .mib |
| mov gp = GR_SAVE_GP // Restore gp |
| mov ar.pfs = GR_SAVE_PFS // Restore ar.pfs |
| br.ret.sptk b0 // Return |
| };; |
| |
| LOCAL_LIBM_END(__libm_error_region) |
| |
| |
| .type __libm_error_support#,@function |
| .global __libm_error_support# |
