diff options
author | José Fonseca <jfonseca@vmware.com> | 2009-10-25 11:48:17 +0000 |
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committer | José Fonseca <jfonseca@vmware.com> | 2009-10-25 11:48:17 +0000 |
commit | e4c5e01c109e51baaad23e90d08e8543b0fd6c07 (patch) | |
tree | 04ea6735454a0e8b69eef114020f69119cce1897 /src/gallium/drivers/llvmpipe/lp_bld_arit.c | |
parent | e1342f871b2ec1ed0293f564540d03aaa11b1720 (diff) |
llvmpipe: Immediate multiplication.
Diffstat (limited to 'src/gallium/drivers/llvmpipe/lp_bld_arit.c')
-rw-r--r-- | src/gallium/drivers/llvmpipe/lp_bld_arit.c | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/src/gallium/drivers/llvmpipe/lp_bld_arit.c b/src/gallium/drivers/llvmpipe/lp_bld_arit.c index 93e797cb44..9c59677a74 100644 --- a/src/gallium/drivers/llvmpipe/lp_bld_arit.c +++ b/src/gallium/drivers/llvmpipe/lp_bld_arit.c @@ -47,6 +47,7 @@ #include "util/u_memory.h" #include "util/u_debug.h" +#include "util/u_math.h" #include "util/u_string.h" #include "util/u_cpu_detect.h" @@ -425,6 +426,59 @@ lp_build_mul(struct lp_build_context *bld, /** + * Small vector x scale multiplication optimization. + */ +LLVMValueRef +lp_build_mul_imm(struct lp_build_context *bld, + LLVMValueRef a, + int b) +{ + LLVMValueRef factor; + + if(b == 0) + return bld->zero; + + if(b == 1) + return a; + + if(b == -1) + return LLVMBuildNeg(bld->builder, a, ""); + + if(b == 2 && bld->type.floating) + return lp_build_add(bld, a, a); + + if(util_is_pot(b)) { + unsigned shift = ffs(b) - 1; + + if(bld->type.floating) { +#if 0 + /* + * Power of two multiplication by directly manipulating the mantissa. + * + * XXX: This might not be always faster, it will introduce a small error + * for multiplication by zero, and it will produce wrong results + * for Inf and NaN. + */ + unsigned mantissa = lp_mantissa(bld->type); + factor = lp_build_int_const_scalar(bld->type, (unsigned long long)shift << mantissa); + a = LLVMBuildBitCast(bld->builder, a, lp_build_int_vec_type(bld->type), ""); + a = LLVMBuildAdd(bld->builder, a, factor, ""); + a = LLVMBuildBitCast(bld->builder, a, lp_build_vec_type(bld->type), ""); + return a; +#endif + } + else { + factor = lp_build_const_scalar(bld->type, shift); + return LLVMBuildShl(bld->builder, a, factor, ""); + } + } + + factor = lp_build_const_scalar(bld->type, (double)b); + return lp_build_mul(bld, a, factor); +} + + +/** * Generate a / b */ LLVMValueRef |