From: Nicolai Hähnle Date: Sun, 11 Oct 2009 15:11:11 +0000 (+0200) Subject: r300/compiler: Implement constant folding X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=1712643a297d66b7a45155fc88937109935687fb;p=mesa.git r300/compiler: Implement constant folding Signed-off-by: Nicolai Hähnle --- diff --git a/src/mesa/drivers/dri/r300/compiler/radeon_optimize.c b/src/mesa/drivers/dri/r300/compiler/radeon_optimize.c index fd608ccb72a..21d72108886 100644 --- a/src/mesa/drivers/dri/r300/compiler/radeon_optimize.c +++ b/src/mesa/drivers/dri/r300/compiler/radeon_optimize.c @@ -28,6 +28,7 @@ #include "radeon_dataflow.h" #include "radeon_compiler.h" +#include "radeon_swizzle.h" static struct rc_src_register chain_srcregs(struct rc_src_register outer, struct rc_src_register inner) @@ -219,6 +220,215 @@ static void peephole(struct radeon_compiler * c, struct rc_instruction * inst_mo rc_remove_instruction(inst_mov); } +/** + * Check if a source register is actually always the same + * swizzle constant. + */ +static int is_src_uniform_constant(struct rc_src_register src, + rc_swizzle * pswz, unsigned int * pnegate) +{ + int have_used = 0; + + if (src.File != RC_FILE_NONE) { + *pswz = 0; + return 0; + } + + for(unsigned int chan = 0; chan < 4; ++chan) { + unsigned int swz = GET_SWZ(src.Swizzle, chan); + if (swz < 4) { + *pswz = 0; + return 0; + } + if (swz == RC_SWIZZLE_UNUSED) + continue; + + if (!have_used) { + *pswz = swz; + *pnegate = GET_BIT(src.Negate, chan); + have_used = 1; + } else { + if (swz != *pswz || *pnegate != GET_BIT(src.Negate, chan)) { + *pswz = 0; + return 0; + } + } + } + + return 1; +} + + +static void constant_folding_mad(struct rc_instruction * inst) +{ + rc_swizzle swz; + unsigned int negate; + + if (is_src_uniform_constant(inst->U.I.SrcReg[2], &swz, &negate)) { + if (swz == RC_SWIZZLE_ZERO) { + inst->U.I.Opcode = RC_OPCODE_MUL; + return; + } + } + + if (is_src_uniform_constant(inst->U.I.SrcReg[1], &swz, &negate)) { + if (swz == RC_SWIZZLE_ONE) { + inst->U.I.Opcode = RC_OPCODE_ADD; + if (negate) + inst->U.I.SrcReg[0].Negate ^= RC_MASK_XYZW; + inst->U.I.SrcReg[1] = inst->U.I.SrcReg[2]; + return; + } else if (swz == RC_SWIZZLE_ZERO) { + inst->U.I.Opcode = RC_OPCODE_MOV; + inst->U.I.SrcReg[0] = inst->U.I.SrcReg[2]; + return; + } + } + + if (is_src_uniform_constant(inst->U.I.SrcReg[0], &swz, &negate)) { + if (swz == RC_SWIZZLE_ONE) { + inst->U.I.Opcode = RC_OPCODE_ADD; + if (negate) + inst->U.I.SrcReg[1].Negate ^= RC_MASK_XYZW; + inst->U.I.SrcReg[0] = inst->U.I.SrcReg[2]; + return; + } else if (swz == RC_SWIZZLE_ZERO) { + inst->U.I.Opcode = RC_OPCODE_MOV; + inst->U.I.SrcReg[0] = inst->U.I.SrcReg[2]; + return; + } + } +} + +static void constant_folding_mul(struct rc_instruction * inst) +{ + rc_swizzle swz; + unsigned int negate; + + if (is_src_uniform_constant(inst->U.I.SrcReg[0], &swz, &negate)) { + if (swz == RC_SWIZZLE_ONE) { + inst->U.I.Opcode = RC_OPCODE_MOV; + inst->U.I.SrcReg[0] = inst->U.I.SrcReg[1]; + if (negate) + inst->U.I.SrcReg[0].Negate ^= RC_MASK_XYZW; + return; + } else if (swz == RC_SWIZZLE_ZERO) { + inst->U.I.Opcode = RC_OPCODE_MOV; + inst->U.I.SrcReg[0].Swizzle = RC_SWIZZLE_0000; + return; + } + } + + if (is_src_uniform_constant(inst->U.I.SrcReg[1], &swz, &negate)) { + if (swz == RC_SWIZZLE_ONE) { + inst->U.I.Opcode = RC_OPCODE_MOV; + if (negate) + inst->U.I.SrcReg[0].Negate ^= RC_MASK_XYZW; + return; + } else if (swz == RC_SWIZZLE_ZERO) { + inst->U.I.Opcode = RC_OPCODE_MOV; + inst->U.I.SrcReg[0].Swizzle = RC_SWIZZLE_0000; + return; + } + } +} + +static void constant_folding_add(struct rc_instruction * inst) +{ + rc_swizzle swz; + unsigned int negate; + + if (is_src_uniform_constant(inst->U.I.SrcReg[0], &swz, &negate)) { + if (swz == RC_SWIZZLE_ZERO) { + inst->U.I.Opcode = RC_OPCODE_MOV; + inst->U.I.SrcReg[0] = inst->U.I.SrcReg[1]; + return; + } + } + + if (is_src_uniform_constant(inst->U.I.SrcReg[1], &swz, &negate)) { + if (swz == RC_SWIZZLE_ZERO) { + inst->U.I.Opcode = RC_OPCODE_MOV; + return; + } + } +} + + +/** + * Replace 0.0, 1.0 and 0.5 immediate constants by their + * respective swizzles. Simplify instructions like ADD dst, src, 0; + */ +static void constant_folding(struct radeon_compiler * c, struct rc_instruction * inst) +{ + const struct rc_opcode_info * opcode = rc_get_opcode_info(inst->U.I.Opcode); + + /* Replace 0.0, 1.0 and 0.5 immediates by their explicit swizzles */ + for(unsigned int src = 0; src < opcode->NumSrcRegs; ++src) { + if (inst->U.I.SrcReg[src].File != RC_FILE_CONSTANT || + inst->U.I.SrcReg[src].RelAddr || + inst->U.I.SrcReg[src].Index >= c->Program.Constants.Count) + continue; + + struct rc_constant * constant = + &c->Program.Constants.Constants[inst->U.I.SrcReg[src].Index]; + + if (constant->Type != RC_CONSTANT_IMMEDIATE) + continue; + + struct rc_src_register newsrc = inst->U.I.SrcReg[src]; + int have_real_reference = 0; + for(unsigned int chan = 0; chan < 4; ++chan) { + unsigned int swz = GET_SWZ(newsrc.Swizzle, chan); + if (swz >= 4) + continue; + + unsigned int newswz; + float imm = constant->u.Immediate[swz]; + float baseimm = imm; + if (imm < 0.0) + baseimm = -baseimm; + + if (baseimm == 0.0) { + newswz = RC_SWIZZLE_ZERO; + } else if (baseimm == 1.0) { + newswz = RC_SWIZZLE_ONE; + } else if (baseimm == 0.5) { + newswz = RC_SWIZZLE_HALF; + } else { + have_real_reference = 1; + continue; + } + + SET_SWZ(newsrc.Swizzle, chan, newswz); + if (imm < 0.0 && !newsrc.Abs) + newsrc.Negate ^= 1 << chan; + } + + if (!have_real_reference) { + newsrc.File = RC_FILE_NONE; + newsrc.Index = 0; + } + + /* don't make the swizzle worse */ + if (!c->SwizzleCaps->IsNative(inst->U.I.Opcode, newsrc) && + c->SwizzleCaps->IsNative(inst->U.I.Opcode, inst->U.I.SrcReg[src])) + continue; + + inst->U.I.SrcReg[src] = newsrc; + } + + /* Simplify instructions based on constants */ + if (inst->U.I.Opcode == RC_OPCODE_MAD) + constant_folding_mad(inst); + + /* note: MAD can simplify to MUL or ADD */ + if (inst->U.I.Opcode == RC_OPCODE_MUL) + constant_folding_mul(inst); + else if (inst->U.I.Opcode == RC_OPCODE_ADD) + constant_folding_add(inst); +} + void rc_optimize(struct radeon_compiler * c) { struct rc_instruction * inst = c->Program.Instructions.Next; @@ -226,7 +436,11 @@ void rc_optimize(struct radeon_compiler * c) struct rc_instruction * cur = inst; inst = inst->Next; - if (cur->U.I.Opcode == RC_OPCODE_MOV) + constant_folding(c, cur); + + if (cur->U.I.Opcode == RC_OPCODE_MOV) { peephole(c, cur); + /* cur may no longer be part of the program */ + } } }