/* -*- c++ -*- */ /* * Copyright © 2010-2015 Intel Corporation * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice (including the next * paragraph) shall be included in all copies or substantial portions of the * Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS * IN THE SOFTWARE. */ #ifndef BRW_VEC4_BUILDER_H #define BRW_VEC4_BUILDER_H #include "brw_ir_vec4.h" #include "brw_ir_allocator.h" namespace brw { /** * Toolbox to assemble a VEC4 IR program out of individual instructions. * * This object is meant to have an interface consistent with * brw::fs_builder. They cannot be fully interchangeable because * brw::fs_builder generates scalar code while brw::vec4_builder generates * vector code. */ class vec4_builder { public: /** Type used in this IR to represent a source of an instruction. */ typedef brw::src_reg src_reg; /** Type used in this IR to represent the destination of an instruction. */ typedef brw::dst_reg dst_reg; /** Type used in this IR to represent an instruction. */ typedef vec4_instruction instruction; /** * Construct a vec4_builder that inserts instructions into \p shader. */ vec4_builder(backend_shader *shader, unsigned dispatch_width = 8) : shader(shader), block(NULL), cursor(NULL), _dispatch_width(dispatch_width), _group(0), force_writemask_all(false), annotation() { } /** * Construct a vec4_builder that inserts instructions into \p shader * before instruction \p inst in basic block \p block. The default * execution controls and debug annotation are initialized from the * instruction passed as argument. */ vec4_builder(backend_shader *shader, bblock_t *block, instruction *inst) : shader(shader), block(block), cursor(inst), _dispatch_width(inst->exec_size), _group(inst->group), force_writemask_all(inst->force_writemask_all) { annotation.str = inst->annotation; annotation.ir = inst->ir; } /** * Construct a vec4_builder that inserts instructions before \p cursor * in basic block \p block, inheriting other code generation parameters * from this. */ vec4_builder at(bblock_t *block, exec_node *cursor) const { vec4_builder bld = *this; bld.block = block; bld.cursor = cursor; return bld; } /** * Construct a vec4_builder appending instructions at the end of the * instruction list of the shader, inheriting other code generation * parameters from this. */ vec4_builder at_end() const { return at(NULL, (exec_node *)&shader->instructions.tail_sentinel); } /** * Construct a builder specifying the default SIMD width and group of * channel enable signals, inheriting other code generation parameters * from this. * * \p n gives the default SIMD width, \p i gives the slot group used for * predication and control flow masking in multiples of \p n channels. */ vec4_builder group(unsigned n, unsigned i) const { assert(force_writemask_all || (n <= dispatch_width() && i < dispatch_width() / n)); vec4_builder bld = *this; bld._dispatch_width = n; bld._group += i * n; return bld; } /** * Construct a builder with per-channel control flow execution masking * disabled if \p b is true. If control flow execution masking is * already disabled this has no effect. */ vec4_builder exec_all(bool b = true) const { vec4_builder bld = *this; if (b) bld.force_writemask_all = true; return bld; } /** * Construct a builder with the given debug annotation info. */ vec4_builder annotate(const char *str, const void *ir = NULL) const { vec4_builder bld = *this; bld.annotation.str = str; bld.annotation.ir = ir; return bld; } /** * Get the SIMD width in use. */ unsigned dispatch_width() const { return _dispatch_width; } /** * Get the channel group in use. */ unsigned group() const { return _group; } /** * Allocate a virtual register of natural vector size (four for this IR) * and SIMD width. \p n gives the amount of space to allocate in * dispatch_width units (which is just enough space for four logical * components in this IR). */ dst_reg vgrf(enum brw_reg_type type, unsigned n = 1) const { assert(dispatch_width() <= 32); if (n > 0) return retype(dst_reg(VGRF, shader->alloc.allocate( n * DIV_ROUND_UP(type_sz(type), 4))), type); else return retype(null_reg_ud(), type); } /** * Create a null register of floating type. */ dst_reg null_reg_f() const { return dst_reg(retype(brw_null_vec(dispatch_width()), BRW_REGISTER_TYPE_F)); } /** * Create a null register of signed integer type. */ dst_reg null_reg_d() const { return dst_reg(retype(brw_null_vec(dispatch_width()), BRW_REGISTER_TYPE_D)); } /** * Create a null register of unsigned integer type. */ dst_reg null_reg_ud() const { return dst_reg(retype(brw_null_vec(dispatch_width()), BRW_REGISTER_TYPE_UD)); } /** * Insert an instruction into the program. */ instruction * emit(const instruction &inst) const { return emit(new(shader->mem_ctx) instruction(inst)); } /** * Create and insert a nullary control instruction into the program. */ instruction * emit(enum opcode opcode) const { return emit(instruction(opcode)); } /** * Create and insert a nullary instruction into the program. */ instruction * emit(enum opcode opcode, const dst_reg &dst) const { return emit(instruction(opcode, dst)); } /** * Create and insert a unary instruction into the program. */ instruction * emit(enum opcode opcode, const dst_reg &dst, const src_reg &src0) const { switch (opcode) { case SHADER_OPCODE_RCP: case SHADER_OPCODE_RSQ: case SHADER_OPCODE_SQRT: case SHADER_OPCODE_EXP2: case SHADER_OPCODE_LOG2: case SHADER_OPCODE_SIN: case SHADER_OPCODE_COS: return fix_math_instruction( emit(instruction(opcode, dst, fix_math_operand(src0)))); default: return emit(instruction(opcode, dst, src0)); } } /** * Create and insert a binary instruction into the program. */ instruction * emit(enum opcode opcode, const dst_reg &dst, const src_reg &src0, const src_reg &src1) const { switch (opcode) { case SHADER_OPCODE_POW: case SHADER_OPCODE_INT_QUOTIENT: case SHADER_OPCODE_INT_REMAINDER: return fix_math_instruction( emit(instruction(opcode, dst, fix_math_operand(src0), fix_math_operand(src1)))); default: return emit(instruction(opcode, dst, src0, src1)); } } /** * Create and insert a ternary instruction into the program. */ instruction * emit(enum opcode opcode, const dst_reg &dst, const src_reg &src0, const src_reg &src1, const src_reg &src2) const { switch (opcode) { case BRW_OPCODE_BFE: case BRW_OPCODE_BFI2: case BRW_OPCODE_MAD: case BRW_OPCODE_LRP: return emit(instruction(opcode, dst, fix_3src_operand(src0), fix_3src_operand(src1), fix_3src_operand(src2))); default: return emit(instruction(opcode, dst, src0, src1, src2)); } } /** * Insert a preallocated instruction into the program. */ instruction * emit(instruction *inst) const { inst->exec_size = dispatch_width(); inst->group = group(); inst->force_writemask_all = force_writemask_all; inst->size_written = inst->exec_size * type_sz(inst->dst.type); inst->annotation = annotation.str; inst->ir = annotation.ir; if (block) static_cast(cursor)->insert_before(block, inst); else cursor->insert_before(inst); return inst; } /** * Select \p src0 if the comparison of both sources with the given * conditional mod evaluates to true, otherwise select \p src1. * * Generally useful to get the minimum or maximum of two values. */ instruction * emit_minmax(const dst_reg &dst, const src_reg &src0, const src_reg &src1, brw_conditional_mod mod) const { assert(mod == BRW_CONDITIONAL_GE || mod == BRW_CONDITIONAL_L); return set_condmod(mod, SEL(dst, fix_unsigned_negate(src0), fix_unsigned_negate(src1))); } /** * Copy any live channel from \p src to the first channel of the result. */ src_reg emit_uniformize(const src_reg &src) const { const vec4_builder ubld = exec_all(); const dst_reg chan_index = writemask(vgrf(BRW_REGISTER_TYPE_UD), WRITEMASK_X); const dst_reg dst = vgrf(src.type); ubld.emit(SHADER_OPCODE_FIND_LIVE_CHANNEL, chan_index); ubld.emit(SHADER_OPCODE_BROADCAST, dst, src, src_reg(chan_index)); return src_reg(dst); } /** * Assorted arithmetic ops. * @{ */ #define ALU1(op) \ instruction * \ op(const dst_reg &dst, const src_reg &src0) const \ { \ return emit(BRW_OPCODE_##op, dst, src0); \ } #define ALU2(op) \ instruction * \ op(const dst_reg &dst, const src_reg &src0, const src_reg &src1) const \ { \ return emit(BRW_OPCODE_##op, dst, src0, src1); \ } #define ALU2_ACC(op) \ instruction * \ op(const dst_reg &dst, const src_reg &src0, const src_reg &src1) const \ { \ instruction *inst = emit(BRW_OPCODE_##op, dst, src0, src1); \ inst->writes_accumulator = true; \ return inst; \ } #define ALU3(op) \ instruction * \ op(const dst_reg &dst, const src_reg &src0, const src_reg &src1, \ const src_reg &src2) const \ { \ return emit(BRW_OPCODE_##op, dst, src0, src1, src2); \ } ALU2(ADD) ALU2_ACC(ADDC) ALU2(AND) ALU2(ASR) ALU2(AVG) ALU3(BFE) ALU2(BFI1) ALU3(BFI2) ALU1(BFREV) ALU1(CBIT) ALU2(CMPN) ALU3(CSEL) ALU1(DIM) ALU2(DP2) ALU2(DP3) ALU2(DP4) ALU2(DPH) ALU1(F16TO32) ALU1(F32TO16) ALU1(FBH) ALU1(FBL) ALU1(FRC) ALU2(LINE) ALU1(LZD) ALU2(MAC) ALU2_ACC(MACH) ALU3(MAD) ALU1(MOV) ALU2(MUL) ALU1(NOT) ALU2(OR) ALU2(PLN) ALU1(RNDD) ALU1(RNDE) ALU1(RNDU) ALU1(RNDZ) ALU2(SAD2) ALU2_ACC(SADA2) ALU2(SEL) ALU2(SHL) ALU2(SHR) ALU2_ACC(SUBB) ALU2(XOR) #undef ALU3 #undef ALU2_ACC #undef ALU2 #undef ALU1 /** @} */ /** * CMP: Sets the low bit of the destination channels with the result * of the comparison, while the upper bits are undefined, and updates * the flag register with the packed 16 bits of the result. */ instruction * CMP(const dst_reg &dst, const src_reg &src0, const src_reg &src1, brw_conditional_mod condition) const { /* Take the instruction: * * CMP null src0 src1 * * Original gen4 does type conversion to the destination type * before comparison, producing garbage results for floating * point comparisons. * * The destination type doesn't matter on newer generations, * so we set the type to match src0 so we can compact the * instruction. */ return set_condmod(condition, emit(BRW_OPCODE_CMP, retype(dst, src0.type), fix_unsigned_negate(src0), fix_unsigned_negate(src1))); } /** * Gen4 predicated IF. */ instruction * IF(brw_predicate predicate) const { return set_predicate(predicate, emit(BRW_OPCODE_IF)); } /** * Gen6 IF with embedded comparison. */ instruction * IF(const src_reg &src0, const src_reg &src1, brw_conditional_mod condition) const { assert(shader->devinfo->gen == 6); return set_condmod(condition, emit(BRW_OPCODE_IF, null_reg_d(), fix_unsigned_negate(src0), fix_unsigned_negate(src1))); } /** * Emit a linear interpolation instruction. */ instruction * LRP(const dst_reg &dst, const src_reg &x, const src_reg &y, const src_reg &a) const { if (shader->devinfo->gen >= 6) { /* The LRP instruction actually does op1 * op0 + op2 * (1 - op0), so * we need to reorder the operands. */ return emit(BRW_OPCODE_LRP, dst, a, y, x); } else { /* We can't use the LRP instruction. Emit x*(1-a) + y*a. */ const dst_reg y_times_a = vgrf(dst.type); const dst_reg one_minus_a = vgrf(dst.type); const dst_reg x_times_one_minus_a = vgrf(dst.type); MUL(y_times_a, y, a); ADD(one_minus_a, negate(a), brw_imm_f(1.0f)); MUL(x_times_one_minus_a, x, src_reg(one_minus_a)); return ADD(dst, src_reg(x_times_one_minus_a), src_reg(y_times_a)); } } backend_shader *shader; protected: /** * Workaround for negation of UD registers. See comment in * fs_generator::generate_code() for the details. */ src_reg fix_unsigned_negate(const src_reg &src) const { if (src.type == BRW_REGISTER_TYPE_UD && src.negate) { dst_reg temp = vgrf(BRW_REGISTER_TYPE_UD); MOV(temp, src); return src_reg(temp); } else { return src; } } /** * Workaround for register access modes not supported by the ternary * instruction encoding. */ src_reg fix_3src_operand(const src_reg &src) const { /* Using vec4 uniforms in SIMD4x2 programs is difficult. You'd like to be * able to use vertical stride of zero to replicate the vec4 uniform, like * * g3<0;4,1>:f - [0, 4][1, 5][2, 6][3, 7] * * But you can't, since vertical stride is always four in three-source * instructions. Instead, insert a MOV instruction to do the replication so * that the three-source instruction can consume it. */ /* The MOV is only needed if the source is a uniform or immediate. */ if (src.file != UNIFORM && src.file != IMM) return src; if (src.file == UNIFORM && brw_is_single_value_swizzle(src.swizzle)) return src; const dst_reg expanded = vgrf(src.type); emit(VEC4_OPCODE_UNPACK_UNIFORM, expanded, src); return src_reg(expanded); } /** * Workaround for register access modes not supported by the math * instruction. */ src_reg fix_math_operand(const src_reg &src) const { /* The gen6 math instruction ignores the source modifiers -- * swizzle, abs, negate, and at least some parts of the register * region description. * * Rather than trying to enumerate all these cases, *always* expand the * operand to a temp GRF for gen6. * * For gen7, keep the operand as-is, except if immediate, which gen7 still * can't use. */ if (shader->devinfo->gen == 6 || (shader->devinfo->gen == 7 && src.file == IMM)) { const dst_reg tmp = vgrf(src.type); MOV(tmp, src); return src_reg(tmp); } else { return src; } } /** * Workaround other weirdness of the math instruction. */ instruction * fix_math_instruction(instruction *inst) const { if (shader->devinfo->gen == 6 && inst->dst.writemask != WRITEMASK_XYZW) { const dst_reg tmp = vgrf(inst->dst.type); MOV(inst->dst, src_reg(tmp)); inst->dst = tmp; } else if (shader->devinfo->gen < 6) { const unsigned sources = (inst->src[1].file == BAD_FILE ? 1 : 2); inst->base_mrf = 1; inst->mlen = sources; } return inst; } bblock_t *block; exec_node *cursor; unsigned _dispatch_width; unsigned _group; bool force_writemask_all; /** Debug annotation info. */ struct { const char *str; const void *ir; } annotation; }; } #endif