From 7a1c4a0ccc56e0b633777b26a9a02d62660a4a1b Mon Sep 17 00:00:00 2001 From: Jason Ekstrand Date: Fri, 8 Jan 2016 16:02:06 -0800 Subject: [PATCH] nir/spirv: Add matrix determinants and inverses --- src/glsl/nir/spirv/vtn_glsl450.c | 155 ++++++++++++++++++++++++++++++- 1 file changed, 151 insertions(+), 4 deletions(-) diff --git a/src/glsl/nir/spirv/vtn_glsl450.c b/src/glsl/nir/spirv/vtn_glsl450.c index 739e4394954..82cfc8c91a9 100644 --- a/src/glsl/nir/spirv/vtn_glsl450.c +++ b/src/glsl/nir/spirv/vtn_glsl450.c @@ -28,6 +28,141 @@ #include "vtn_private.h" #include "GLSL.std.450.h" +static nir_ssa_def * +build_mat2_det(nir_builder *b, nir_ssa_def *col[2]) +{ + unsigned swiz[4] = {1, 0, 0, 0}; + nir_ssa_def *p = nir_fmul(b, col[0], nir_swizzle(b, col[1], swiz, 2, true)); + return nir_fsub(b, nir_channel(b, p, 0), nir_channel(b, p, 1)); +} + +static nir_ssa_def * +build_mat3_det(nir_builder *b, nir_ssa_def *col[3]) +{ + unsigned yzx[4] = {1, 2, 0, 0}; + unsigned zxy[4] = {2, 0, 1, 0}; + + nir_ssa_def *prod0 = + nir_fmul(b, col[0], + nir_fmul(b, nir_swizzle(b, col[1], yzx, 3, true), + nir_swizzle(b, col[2], zxy, 3, true))); + nir_ssa_def *prod1 = + nir_fmul(b, col[0], + nir_fmul(b, nir_swizzle(b, col[1], zxy, 3, true), + nir_swizzle(b, col[2], yzx, 3, true))); + + nir_ssa_def *diff = nir_fsub(b, prod0, prod1); + + return nir_fadd(b, nir_channel(b, diff, 0), + nir_fadd(b, nir_channel(b, diff, 1), + nir_channel(b, diff, 2))); +} + +static nir_ssa_def * +build_mat4_det(nir_builder *b, nir_ssa_def **col) +{ + nir_ssa_def *subdet[4]; + for (unsigned i = 0; i < 4; i++) { + unsigned swiz[3]; + for (unsigned j = 0; j < 4; j++) + swiz[j - (j > i)] = j; + + nir_ssa_def *subcol[3]; + subcol[0] = nir_swizzle(b, col[1], swiz, 3, true); + subcol[1] = nir_swizzle(b, col[2], swiz, 3, true); + subcol[2] = nir_swizzle(b, col[3], swiz, 3, true); + + subdet[i] = build_mat3_det(b, subcol); + } + + nir_ssa_def *prod = nir_fmul(b, col[0], nir_vec(b, subdet, 4)); + + return nir_fadd(b, nir_fsub(b, nir_channel(b, prod, 0), + nir_channel(b, prod, 1)), + nir_fsub(b, nir_channel(b, prod, 2), + nir_channel(b, prod, 3))); +} + +static nir_ssa_def * +build_mat_det(struct vtn_builder *b, struct vtn_ssa_value *src) +{ + unsigned size = glsl_get_vector_elements(src->type); + + nir_ssa_def *cols[4]; + for (unsigned i = 0; i < size; i++) + cols[i] = src->elems[i]->def; + + switch(size) { + case 2: return build_mat2_det(&b->nb, cols); + case 3: return build_mat3_det(&b->nb, cols); + case 4: return build_mat4_det(&b->nb, cols); + default: + unreachable("Invalid matrix size"); + } +} + +/* Computes the determinate of the submatrix given by taking src and + * removing the specified row and column. + */ +static nir_ssa_def * +build_mat_subdet(struct nir_builder *b, struct vtn_ssa_value *src, + unsigned size, unsigned row, unsigned col) +{ + assert(row < size && col < size); + if (size == 2) { + return nir_channel(b, src->elems[1 - col]->def, 1 - row); + } else { + /* Swizzle to get all but the specified row */ + unsigned swiz[3]; + for (unsigned j = 0; j < 4; j++) + swiz[j - (j > row)] = j; + + /* Grab all but the specified column */ + nir_ssa_def *subcol[3]; + for (unsigned j = 0; j < size; j++) { + if (j != col) { + subcol[j - (j > col)] = nir_swizzle(b, src->elems[j]->def, + swiz, size - 1, true); + } + } + + if (size == 3) { + return build_mat2_det(b, subcol); + } else { + assert(size == 4); + return build_mat3_det(b, subcol); + } + } +} + +static struct vtn_ssa_value * +matrix_inverse(struct vtn_builder *b, struct vtn_ssa_value *src) +{ + nir_ssa_def *adj_col[4]; + unsigned size = glsl_get_vector_elements(src->type); + + /* Build up an adjugate matrix */ + for (unsigned c = 0; c < size; c++) { + nir_ssa_def *elem[4]; + for (unsigned r = 0; r < size; r++) { + elem[r] = build_mat_subdet(&b->nb, src, size, c, r); + + if ((r + c) % 2) + elem[r] = nir_fneg(&b->nb, elem[r]); + } + + adj_col[c] = nir_vec(&b->nb, elem, size); + } + + nir_ssa_def *det_inv = nir_frcp(&b->nb, build_mat_det(b, src)); + + struct vtn_ssa_value *val = vtn_create_ssa_value(b, src->type); + for (unsigned i = 0; i < size; i++) + val->elems[i]->def = nir_fmul(&b->nb, adj_col[i], det_inv); + + return val; +} + static nir_ssa_def* build_length(nir_builder *b, nir_ssa_def *vec) { @@ -309,18 +444,30 @@ handle_glsl450_alu(struct vtn_builder *b, enum GLSLstd450 entrypoint, bool vtn_handle_glsl450_instruction(struct vtn_builder *b, uint32_t ext_opcode, - const uint32_t *words, unsigned count) + const uint32_t *w, unsigned count) { switch ((enum GLSLstd450)ext_opcode) { - case GLSLstd450Determinant: - case GLSLstd450MatrixInverse: + case GLSLstd450Determinant: { + struct vtn_value *val = vtn_push_value(b, w[2], vtn_value_type_ssa); + val->ssa = rzalloc(b, struct vtn_ssa_value); + val->ssa->type = vtn_value(b, w[1], vtn_value_type_type)->type->type; + val->ssa->def = build_mat_det(b, vtn_ssa_value(b, w[5])); + break; + } + + case GLSLstd450MatrixInverse: { + struct vtn_value *val = vtn_push_value(b, w[2], vtn_value_type_ssa); + val->ssa = matrix_inverse(b, vtn_ssa_value(b, w[5])); + break; + } + case GLSLstd450InterpolateAtCentroid: case GLSLstd450InterpolateAtSample: case GLSLstd450InterpolateAtOffset: unreachable("Unhandled opcode"); default: - handle_glsl450_alu(b, (enum GLSLstd450)ext_opcode, words, count); + handle_glsl450_alu(b, (enum GLSLstd450)ext_opcode, w, count); } return true; -- 2.30.2