I only check the correctness, there is no problem It seems mix using tab and space in the function __gen_ocl_internal_simple_exp and there some intend problem.
-----Original Message----- From: Beignet [mailto:beignet-boun...@lists.freedesktop.org] On Behalf Of rander.wang Sent: Wednesday, June 7, 2017 13:49 To: beig...@freedesktop.org Cc: Wang, Rander <rander.w...@intel.com> Subject: [Beignet] [PATCH] backend: refine exp function with float input remove some corner cases check for these path can not be reached.And refine branch code to select. These improvements get 20% performance. and the performance of OCL_ExpFixture_Exp in opencv can match up to other Gen driver Signed-off-by: rander.wang <rander.w...@intel.com> --- backend/src/libocl/tmpl/ocl_math_common.tmpl.cl | 60 ++++++++++++++++++++++++- 1 file changed, 58 insertions(+), 2 deletions(-) diff --git a/backend/src/libocl/tmpl/ocl_math_common.tmpl.cl b/backend/src/libocl/tmpl/ocl_math_common.tmpl.cl index 6b942db..16bbc82 100644 --- a/backend/src/libocl/tmpl/ocl_math_common.tmpl.cl +++ b/backend/src/libocl/tmpl/ocl_math_common.tmpl.cl @@ -1418,6 +1418,62 @@ OVERLOADABLE float __gen_ocl_internal_exp(float x) { } } +OVERLOADABLE float __gen_ocl_internal_simple_exp(float x) { + float o_threshold = 8.8721679688e+01, /* 0x42b17180 */ + u_threshold = -1.0397208405e+02, /* 0xc2cff1b5 */ + twom100 = 7.8886090522e-31, /* 2**-100=0x0d800000 */ + ivln2 = 1.4426950216e+00, /* 0x3fb8aa3b =1/ln2 */ + one = 1.0, + P1 = 1.6666667163e-01, /* 0x3e2aaaab */ + P2 = -2.7777778450e-03; /* 0xbb360b61 */ + float y,hi=0.0,lo=0.0,c,t; + int k=0; + unsigned hx; + float ln2HI_0 = 6.9313812256e-01; /* 0x3f317180 */ + float ln2HI_1 = -6.9313812256e-01; /* 0xbf317180 */ + float ln2LO_0 = 9.0580006145e-06; /* 0x3717f7d1 */ + float ln2LO_1 = -9.0580006145e-06; /* 0xb717f7d1 */ + float half_0 = 0.5; + float half_1 = -0.5; + float retVal = -1.0f; + hx = as_uint(fabs(x)); + + /* filter out non-finite argument */ + /* if |x|>=88.721... */ + if(hx >= 0x42b17218) + { + float tmp = (x > 0)? x:0.0; + retVal = (x > 0)? INFINITY:retVal; /* overflow */ + retVal = (hx>0x7f800000)? NAN:retVal; + retVal = (hx==0x7f800000)? tmp:retVal; + retVal = (x < u_threshold)? 0.0:retVal; /* underflow */ + + if(retVal != -1.0f) + return retVal; + } + + /* argument reduction */ + float tmp = (x < 0) ? half_1 : half_0; k = mad(ivln2, x, tmp); t + = k; + hi = mad(t, -ln2HI_0, x); /* t*ln2HI is exact here */ + lo = t*ln2LO_0; + x = hi - lo; + + /* x is now in primary range */ + t = x*x; + c = mad(t, mad(t, -P2, -P1), x); + y = one-((lo + (x*c)/(c-2.0f))-hi); + + unsigned hy; + GEN_OCL_GET_FLOAT_WORD(hy,y); + + float factor = (k >= -125)? 1.0f:twom100; + k = (k >= -125)? k:k+100; + GEN_OCL_SET_FLOAT_WORD(y,hy+(k<<23)); /* add k to y's exponent */ + return y*factor; +} + /* erf,erfc from glibc s_erff.c -- float version of s_erf.c. * Conversion to float by Ian Lance Taylor, Cygnus Support, i...@cygnus.com. */ @@ -3105,10 +3161,10 @@ OVERLOADABLE float exp(float x) { return __gen_ocl_internal_fastpath_exp(x); /* Use native instruction when it has enough precision */ - if (x > -0x1.6p1 && x < 0x1.6p1) + if (fabs(x) < 0x1.6p1) return __gen_ocl_internal_fastpath_exp(x); - return __gen_ocl_internal_exp(x); + return __gen_ocl_internal_simple_exp(x); } OVERLOADABLE float exp2(float x) { -- 2.7.4 _______________________________________________ Beignet mailing list Beignet@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/beignet _______________________________________________ Beignet mailing list Beignet@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/beignet