/* -*- 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_FS_BUILDER_H
#define BRW_FS_BUILDER_H
#include "brw_ir_fs.h"
#include "brw_shader.h"
#include "brw_context.h"
namespace brw {
/**
* Toolbox to assemble an FS IR program out of individual instructions.
*
* This object is meant to have an interface consistent with
* brw::vec4_builder. They cannot be fully interchangeable because
* brw::fs_builder generates scalar code while brw::vec4_builder generates
* vector code.
*/
class fs_builder {
public:
/** Type used in this IR to represent a source of an instruction. */
typedef fs_reg src_reg;
/** Type used in this IR to represent the destination of an instruction. */
typedef fs_reg dst_reg;
/** Type used in this IR to represent an instruction. */
typedef fs_inst instruction;
/**
* Construct an fs_builder that inserts instructions into \p shader.
* \p dispatch_width gives the native execution width of the program.
*/
fs_builder(backend_shader *shader,
unsigned dispatch_width) :
shader(shader), block(NULL), cursor(NULL),
_dispatch_width(dispatch_width),
_group(0),
force_writemask_all(false),
annotation()
{
}
/**
* Construct an fs_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.
*/
fs_builder(backend_shader *shader, bblock_t *block, fs_inst *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 an fs_builder that inserts instructions before \p cursor in
* basic block \p block, inheriting other code generation parameters
* from this.
*/
fs_builder
at(bblock_t *block, exec_node *cursor) const
{
fs_builder bld = *this;
bld.block = block;
bld.cursor = cursor;
return bld;
}
/**
* Construct an fs_builder appending instructions at the end of the
* instruction list of the shader, inheriting other code generation
* parameters from this.
*/
fs_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.
*/
fs_builder
group(unsigned n, unsigned i) const
{
assert(force_writemask_all ||
(n <= dispatch_width() && i < dispatch_width() / n));
fs_builder bld = *this;
bld._dispatch_width = n;
bld._group += i * n;
return bld;
}
/**
* Alias for group() with width equal to eight.
*/
fs_builder
half(unsigned i) const
{
return group(8, i);
}
/**
* 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.
*/
fs_builder
exec_all(bool b = true) const
{
fs_builder bld = *this;
if (b)
bld.force_writemask_all = true;
return bld;
}
/**
* Construct a builder with the given debug annotation info.
*/
fs_builder
annotate(const char *str, const void *ir = NULL) const
{
fs_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 (one 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 one logical
* component in this IR).
*/
dst_reg
vgrf(enum brw_reg_type type, unsigned n = 1) const
{
assert(dispatch_width() <= 32);
if (n > 0)
return dst_reg(VGRF, shader->alloc.allocate(
DIV_ROUND_UP(n * type_sz(type) * dispatch_width(),
REG_SIZE)),
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_reg(), BRW_REGISTER_TYPE_F));
}
dst_reg
null_reg_df() const
{
return dst_reg(retype(brw_null_reg(), BRW_REGISTER_TYPE_DF));
}
/**
* Create a null register of signed integer type.
*/
dst_reg
null_reg_d() const
{
return dst_reg(retype(brw_null_reg(), BRW_REGISTER_TYPE_D));
}
/**
* Create a null register of unsigned integer type.
*/
dst_reg
null_reg_ud() const
{
return dst_reg(retype(brw_null_reg(), BRW_REGISTER_TYPE_UD));
}
/**
* Get the mask of SIMD channels enabled by dispatch and not yet
* disabled by discard.
*/
src_reg
sample_mask_reg() const
{
assert(shader->stage != MESA_SHADER_FRAGMENT ||
group() + dispatch_width() <= 16);
if (shader->stage != MESA_SHADER_FRAGMENT) {
return brw_imm_d(0xffffffff);
} else if (brw_wm_prog_data(shader->stage_prog_data)->uses_kill) {
return brw_flag_reg(0, 1);
} else {
return retype(brw_vec1_grf(1, 7), 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, dispatch_width()));
}
/**
* Create and insert a nullary instruction into the program.
*/
instruction *
emit(enum opcode opcode, const dst_reg &dst) const
{
return emit(instruction(opcode, dispatch_width(), 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 emit(instruction(opcode, dispatch_width(), dst,
fix_math_operand(src0)));
default:
return emit(instruction(opcode, dispatch_width(), 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 emit(instruction(opcode, dispatch_width(), dst,
fix_math_operand(src0),
fix_math_operand(src1)));
default:
return emit(instruction(opcode, dispatch_width(), 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, dispatch_width(), dst,
fix_3src_operand(src0),
fix_3src_operand(src1),
fix_3src_operand(src2)));
default:
return emit(instruction(opcode, dispatch_width(), dst,
src0, src1, src2));
}
}
/**
* Create and insert an instruction with a variable number of sources
* into the program.
*/
instruction *
emit(enum opcode opcode, const dst_reg &dst, const src_reg srcs[],
unsigned n) const
{
return emit(instruction(opcode, dispatch_width(), dst, srcs, n));
}
/**
* Insert a preallocated instruction into the program.
*/
instruction *
emit(instruction *inst) const
{
assert(inst->exec_size <= 32);
assert(inst->exec_size == dispatch_width() ||
force_writemask_all);
inst->group = _group;
inst->force_writemask_all = force_writemask_all;
inst->annotation = annotation.str;
inst->ir = annotation.ir;
if (block)
static_cast<instruction *>(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
{
/* FIXME: We use a vector chan_index and dst to allow constant and
* copy propagration to move result all the way into the consuming
* instruction (typically a surface index or sampler index for a
* send). This uses 1 or 3 extra hw registers in 16 or 32 wide
* dispatch. Once we teach const/copy propagation about scalars we
* should go back to scalar destinations here.
*/
const fs_builder ubld = exec_all();
const dst_reg chan_index = vgrf(BRW_REGISTER_TYPE_UD);
const dst_reg dst = vgrf(src.type);
ubld.emit(SHADER_OPCODE_FIND_LIVE_CHANNEL, chan_index);
ubld.emit(SHADER_OPCODE_BROADCAST, dst, src, component(chan_index, 0));
return src_reg(component(dst, 0));
}
/**
* 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<d> src0<f> src1<f>
*
* 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));
}
/**
* 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));
}
}
/**
* Collect a number of registers in a contiguous range of registers.
*/
instruction *
LOAD_PAYLOAD(const dst_reg &dst, const src_reg *src,
unsigned sources, unsigned header_size) const
{
instruction *inst = emit(SHADER_OPCODE_LOAD_PAYLOAD, dst, src, sources);
inst->header_size = header_size;
inst->size_written = header_size * REG_SIZE;
for (unsigned i = header_size; i < sources; i++) {
inst->size_written +=
ALIGN(dispatch_width() * type_sz(src[i].type) * dst.stride,
REG_SIZE);
}
return inst;
}
backend_shader *shader;
private:
/**
* Workaround for negation of UD registers. See comment in
* fs_generator::generate_code() for more 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 source register modes not supported by the ternary
* instruction encoding.
*/
src_reg
fix_3src_operand(const src_reg &src) const
{
if (src.file == VGRF || src.file == UNIFORM || src.stride > 1) {
return src;
} else {
dst_reg expanded = vgrf(src.type);
MOV(expanded, src);
return expanded;
}
}
/**
* Workaround for source register modes not supported by the math
* instruction.
*/
src_reg
fix_math_operand(const src_reg &src) const
{
/* Can't do hstride == 0 args on gen6 math, so expand it out. We
* might be able to do better by doing execsize = 1 math and then
* expanding that result out, but we would need to be careful with
* masking.
*
* Gen6 hardware ignores source modifiers (negate and abs) on math
* instructions, so we also move to a temp to set those up.
*
* Gen7 relaxes most of the above restrictions, but still can't use IMM
* operands to math
*/
if ((shader->devinfo->gen == 6 &&
(src.file == IMM || src.file == UNIFORM ||
src.abs || src.negate)) ||
(shader->devinfo->gen == 7 && src.file == IMM)) {
const dst_reg tmp = vgrf(src.type);
MOV(tmp, src);
return tmp;
} else {
return src;
}
}
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