diff options
author | Michal Krol <michal@tungstengraphics.com> | 2008-11-12 23:23:49 +0100 |
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committer | Michal Krol <michal@tungstengraphics.com> | 2008-11-12 23:25:43 +0100 |
commit | 26c8593093bd9e42d06a54ed8cfdedce2fb44332 (patch) | |
tree | 5fd039fc040c33fd974db1196e4e7e39dbc8631e /src/gallium/auxiliary/tgsi/tgsi_exec.c | |
parent | 44257a8e752a5f10aed7e5797b23cdb42120703c (diff) |
tgsi: More comments on source register indirect and 2D indexing.
Diffstat (limited to 'src/gallium/auxiliary/tgsi/tgsi_exec.c')
-rw-r--r-- | src/gallium/auxiliary/tgsi/tgsi_exec.c | 65 |
1 files changed, 55 insertions, 10 deletions
diff --git a/src/gallium/auxiliary/tgsi/tgsi_exec.c b/src/gallium/auxiliary/tgsi/tgsi_exec.c index 1da04ab7e0..4a217454dd 100644 --- a/src/gallium/auxiliary/tgsi/tgsi_exec.c +++ b/src/gallium/auxiliary/tgsi/tgsi_exec.c @@ -1037,11 +1037,28 @@ fetch_source( union tgsi_exec_channel index; uint swizzle; + /* We start with a direct index into a register file. + * + * file[1], + * where: + * file = SrcRegister.File + * [1] = SrcRegister.Index + */ index.i[0] = index.i[1] = index.i[2] = index.i[3] = reg->SrcRegister.Index; + /* There is an extra source register that indirectly subscripts + * a register file. The direct index now becomes an offset + * that is being added to the indirect register. + * + * file[ind[2].x+1], + * where: + * ind = SrcRegisterInd.File + * [2] = SrcRegisterInd.Index + * .x = SrcRegisterInd.SwizzleX + */ if (reg->SrcRegister.Indirect) { union tgsi_exec_channel index2; union tgsi_exec_channel indir_index; @@ -1078,19 +1095,31 @@ fetch_source( } } - if( reg->SrcRegister.Dimension ) { - switch( reg->SrcRegister.File ) { + /* There is an extra source register that is a second + * subscript to a register file. Effectively it means that + * the register file is actually a 2D array of registers. + * + * file[1][3] == file[1*sizeof(file[1])+3], + * where: + * [3] = SrcRegisterDim.Index + */ + if (reg->SrcRegister.Dimension) { + /* The size of the first-order array depends on the register file type. + * We need to multiply the index to the first array to get an effective, + * "flat" index that points to the beginning of the second-order array. + */ + switch (reg->SrcRegister.File) { case TGSI_FILE_INPUT: - index.i[0] *= 17; - index.i[1] *= 17; - index.i[2] *= 17; - index.i[3] *= 17; + index.i[0] *= TGSI_EXEC_MAX_INPUT_ATTRIBS; + index.i[1] *= TGSI_EXEC_MAX_INPUT_ATTRIBS; + index.i[2] *= TGSI_EXEC_MAX_INPUT_ATTRIBS; + index.i[3] *= TGSI_EXEC_MAX_INPUT_ATTRIBS; break; case TGSI_FILE_CONSTANT: - index.i[0] *= 4096; - index.i[1] *= 4096; - index.i[2] *= 4096; - index.i[3] *= 4096; + index.i[0] *= TGSI_EXEC_MAX_CONST_BUFFER; + index.i[1] *= TGSI_EXEC_MAX_CONST_BUFFER; + index.i[2] *= TGSI_EXEC_MAX_CONST_BUFFER; + index.i[3] *= TGSI_EXEC_MAX_CONST_BUFFER; break; default: assert( 0 ); @@ -1101,6 +1130,17 @@ fetch_source( index.i[2] += reg->SrcRegisterDim.Index; index.i[3] += reg->SrcRegisterDim.Index; + /* Again, the second subscript index can be addressed indirectly + * identically to the first one. + * Nothing stops us from indirectly addressing the indirect register, + * but there is no need for that, so we won't exercise it. + * + * file[1][ind[4].y+3], + * where: + * ind = SrcRegisterDimInd.File + * [4] = SrcRegisterDimInd.Index + * .y = SrcRegisterDimInd.SwizzleX + */ if (reg->SrcRegisterDim.Indirect) { union tgsi_exec_channel index2; union tgsi_exec_channel indir_index; @@ -1133,6 +1173,11 @@ fetch_source( index.i[i] = 0; } } + + /* If by any chance there was a need for a 3D array of register + * files, we would have to check whether SrcRegisterDim is followed + * by a dimension register and continue the saga. + */ } swizzle = tgsi_util_get_full_src_register_extswizzle( reg, chan_index ); |