From: José Fonseca Date: Fri, 21 Aug 2009 06:35:49 +0000 (+0100) Subject: llvmpipe: Clamped float to unsigned norm via mantissa manipulation. X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=3dbf00f9ab0d2e771c72a74d9db32c048ce7df4e;p=mesa.git llvmpipe: Clamped float to unsigned norm via mantissa manipulation. --- diff --git a/src/gallium/drivers/llvmpipe/lp_bld_conv.c b/src/gallium/drivers/llvmpipe/lp_bld_conv.c index 10a8d61e0de..520052cb69a 100644 --- a/src/gallium/drivers/llvmpipe/lp_bld_conv.c +++ b/src/gallium/drivers/llvmpipe/lp_bld_conv.c @@ -46,6 +46,7 @@ #include "util/u_debug.h" +#include "util/u_math.h" #include "lp_bld_type.h" #include "lp_bld_const.h" @@ -54,6 +55,79 @@ #include "lp_bld_conv.h" +LLVMValueRef +lp_build_clamped_float_to_unsigned_norm(LLVMBuilderRef builder, + union lp_type src_type, + unsigned dst_width, + LLVMValueRef src) +{ + LLVMTypeRef int_vec_type = lp_build_int_vec_type(src_type); + LLVMValueRef res; + unsigned mantissa; + unsigned n; + unsigned long long ubound; + unsigned long long mask; + double scale; + double bias; + + assert(src_type.floating); + + switch(src_type.width) { + case 32: + mantissa = 23; + break; + case 64: + mantissa = 53; + break; + default: + assert(0); + return LLVMGetUndef(int_vec_type); + } + + /* We cannot carry more bits than the mantissa */ + n = MIN2(mantissa, dst_width); + + /* This magic coefficients will make the desired result to appear in the + * lowest significant bits of the mantissa. + */ + ubound = ((unsigned long long)1 << n); + mask = ubound - 1; + scale = (double)mask/ubound; + bias = (double)((unsigned long long)1 << (mantissa - n)); + + res = LLVMBuildMul(builder, src, lp_build_const_uni(src_type, scale), ""); + res = LLVMBuildAdd(builder, res, lp_build_const_uni(src_type, bias), ""); + res = LLVMBuildBitCast(builder, res, int_vec_type, ""); + + if(dst_width < src_type.width) + res = LLVMBuildAnd(builder, res, lp_build_int_const_uni(src_type, mask), ""); + + if(dst_width > n) { + int shift = dst_width - n; + res = LLVMBuildShl(builder, res, lp_build_int_const_uni(src_type, shift), ""); + + /* Fill in the empty lower bits for added precision? */ +#if 0 + { + LLVMValueRef msb; + msb = LLVMBuildLShr(builder, res, lp_build_int_const_uni(src_type, dst_width - 1), ""); + msb = LLVMBuildShl(builder, msb, lp_build_int_const_uni(src_type, shift), ""); + msb = LLVMBuildSub(builder, msb, lp_build_int_const_uni(src_type, 1), ""); + res = LLVMBuildOr(builder, res, msb, ""); + } +#elif 0 + while(shift > 0) { + res = LLVMBuildOr(builder, res, LLVMBuildLShr(builder, res, lp_build_int_const_uni(src_type, n), ""), ""); + shift -= n; + n *= 2; + } +#endif + } + + return res; +} + + /** * Build shuffle vectors that match PUNPCKLxx and PUNPCKHxx instructions. */ @@ -259,28 +333,39 @@ lp_build_conv(LLVMBuilderRef builder, /* Nothing to do */ } else if(tmp_type.floating) { - double dst_scale = lp_const_scale(dst_type); - LLVMTypeRef tmp_vec_type; - - if (dst_scale != 1.0) { - LLVMValueRef scale = lp_build_const_uni(tmp_type, dst_scale); - for(i = 0; i < num_tmps; ++i) - tmp[i] = LLVMBuildMul(builder, tmp[i], scale, ""); + if(!dst_type.fixed && !dst_type.sign && dst_type.norm) { + for(i = 0; i < num_tmps; ++i) { + tmp[i] = lp_build_clamped_float_to_unsigned_norm(builder, + tmp_type, + dst_type.width, + tmp[i]); + } + tmp_type.floating = FALSE; } + else { + double dst_scale = lp_const_scale(dst_type); + LLVMTypeRef tmp_vec_type; + + if (dst_scale != 1.0) { + LLVMValueRef scale = lp_build_const_uni(tmp_type, dst_scale); + for(i = 0; i < num_tmps; ++i) + tmp[i] = LLVMBuildMul(builder, tmp[i], scale, ""); + } - /* Use an equally sized integer for intermediate computations */ - tmp_type.floating = FALSE; - tmp_vec_type = lp_build_vec_type(tmp_type); - for(i = 0; i < num_tmps; ++i) { + /* Use an equally sized integer for intermediate computations */ + tmp_type.floating = FALSE; + tmp_vec_type = lp_build_vec_type(tmp_type); + for(i = 0; i < num_tmps; ++i) { #if 0 - if(dst_type.sign) - tmp[i] = LLVMBuildFPToSI(builder, tmp[i], tmp_vec_type, ""); - else - tmp[i] = LLVMBuildFPToUI(builder, tmp[i], tmp_vec_type, ""); + if(dst_type.sign) + tmp[i] = LLVMBuildFPToSI(builder, tmp[i], tmp_vec_type, ""); + else + tmp[i] = LLVMBuildFPToUI(builder, tmp[i], tmp_vec_type, ""); #else - /* FIXME: there is no SSE counterpart for LLVMBuildFPToUI */ - tmp[i] = LLVMBuildFPToSI(builder, tmp[i], tmp_vec_type, ""); + /* FIXME: there is no SSE counterpart for LLVMBuildFPToUI */ + tmp[i] = LLVMBuildFPToSI(builder, tmp[i], tmp_vec_type, ""); #endif + } } } else { diff --git a/src/gallium/drivers/llvmpipe/lp_bld_conv.h b/src/gallium/drivers/llvmpipe/lp_bld_conv.h index 0ccd4766a00..b1e3da7e9ce 100644 --- a/src/gallium/drivers/llvmpipe/lp_bld_conv.h +++ b/src/gallium/drivers/llvmpipe/lp_bld_conv.h @@ -43,6 +43,13 @@ union lp_type type; +LLVMValueRef +lp_build_clamped_float_to_unsigned_norm(LLVMBuilderRef builder, + union lp_type src_type, + unsigned dst_width, + LLVMValueRef src); + + void lp_build_conv(LLVMBuilderRef builder, union lp_type src_type, diff --git a/src/gallium/drivers/llvmpipe/lp_test.h b/src/gallium/drivers/llvmpipe/lp_test.h index c51399f8079..69aaae26e0a 100644 --- a/src/gallium/drivers/llvmpipe/lp_test.h +++ b/src/gallium/drivers/llvmpipe/lp_test.h @@ -113,6 +113,10 @@ void random_vec(union lp_type type, void *dst); +boolean +compare_vec_with_eps(union lp_type type, const void *res, const void *ref, double eps); + + boolean compare_vec(union lp_type type, const void *res, const void *ref);