[Mesa-dev] [PATCH 1/2] r600g: rework handling of the constants
Vincent
vljn at ovi.com
Mon Dec 31 10:39:11 PST 2012
Le dimanche 30 décembre 2012 à 10:29 -0500, Tom Stellard a écrit :
> On Wed, Dec 26, 2012 at 05:38:27PM +0100, Vincent Lejeune wrote:
> > From Vadim Girlin patch
> > ---
> > src/gallium/drivers/r600/r600_llvm.c | 27 +++++++++++----
> > src/gallium/drivers/r600/r600_shader.c | 39 ++++++++++++++++------
> > .../drivers/radeon/radeon_setup_tgsi_llvm.c | 4 +++
> > 3 files changed, 54 insertions(+), 16 deletions(-)
> >
> > diff --git a/src/gallium/drivers/r600/r600_llvm.c b/src/gallium/drivers/r600/r600_llvm.c
> > index 79f6cf0..cae2131 100644
> > --- a/src/gallium/drivers/r600/r600_llvm.c
> > +++ b/src/gallium/drivers/r600/r600_llvm.c
> > @@ -25,12 +25,19 @@ static LLVMValueRef llvm_fetch_const(
> > enum tgsi_opcode_type type,
> > unsigned swizzle)
> > {
> > - LLVMValueRef idx = lp_build_const_int32(bld_base->base.gallivm,
> > - radeon_llvm_reg_index_soa(reg->Register.Index, swizzle));
> > - LLVMValueRef cval = build_intrinsic(bld_base->base.gallivm->builder,
> > - "llvm.AMDGPU.load.const", bld_base->base.elem_type,
> > - &idx, 1, LLVMReadNoneAttribute);
> > -
> > + LLVMValueRef offset[2] = {
> > + LLVMConstInt(LLVMInt64TypeInContext(bld_base->base.gallivm->context), 0, false),
> > + lp_build_const_int32(bld_base->base.gallivm, reg->Register.Index)
> > + };
> > + if (reg->Register.Indirect) {
> > + struct lp_build_tgsi_soa_context *bld = lp_soa_context(bld_base);
> > + LLVMValueRef index = LLVMBuildLoad(bld_base->base.gallivm->builder, bld->addr[reg->Indirect.Index][reg->Indirect.SwizzleX], "");
> > + offset[1] = LLVMBuildAdd(bld_base->base.gallivm->builder, offset[1], index, "");
> > + }
> > + LLVMValueRef const_ptr = LLVMGetFirstGlobal(bld_base->base.gallivm->module);
> > + LLVMValueRef ptr = LLVMBuildGEP(bld_base->base.gallivm->builder, const_ptr, offset, 2, "");
> > + LLVMValueRef cvecval = LLVMBuildLoad(bld_base->base.gallivm->builder, ptr, "");
> > + LLVMValueRef cval = LLVMBuildExtractElement(bld_base->base.gallivm->builder, cvecval, lp_build_const_int32(bld_base->base.gallivm, swizzle), "");
> > return bitcast(bld_base, type, cval);
> > }
>
> I thought it would be possible to implement this without using global
> addresses by passing the offset as a pointer to the backend and letting
> the backend figure out how to translate it into a kcache address.
> Can you explain why we are using global variables here?
>
> -Tom
The main drawback from the offset as a pointer solution is that it does
not allow to handle multiple const buffers read. R600g already needs to
fetch value from non-default const buffer for clip vertex ; it currently
appends some alus to llvm backend output but this part would better fit
inside the backend IMHO.
I use global variable because it allows to name pointers and thus to
associate a const buffer id with a name (actually "const0" stands for
the default const buffer, "const1" is for the second const buffer, and
so on).
I don't really use the fact it is a global variable inside the backend,
in fact any named pointer marked as external could fit (iirc the
"external symbol" llvm value could be used too ). Global variables
purpose is to model address (function and/or variables) whose value is
know at compile time, whereas ExternalSymbol is for address whose value
is only know at link time.
Vincent
>
> >
> > @@ -449,6 +456,14 @@ LLVMModuleRef r600_tgsi_llvm(
> > bld_base->op_actions[TGSI_OPCODE_TXP].emit = llvm_emit_tex;
> > bld_base->op_actions[TGSI_OPCODE_CMP].emit = emit_cndlt;
> >
> > + // Generate const buffer pointers
> > + for (unsigned i = 0; i < 16; i++) {
> > + char name[8];
> > + sprintf(name, "const%d", i);
> > + LLVMTypeRef type = LLVMArrayType(LLVMVectorType(bld_base->base.elem_type, 4), 1024);
> > + LLVMAddGlobalInAddressSpace(bld_base->base.gallivm->module, type, name, 2);
> > + }
> > +
> > lp_build_tgsi_llvm(bld_base, tokens);
> >
> > radeon_llvm_finalize_module(ctx);
> > diff --git a/src/gallium/drivers/r600/r600_shader.c b/src/gallium/drivers/r600/r600_shader.c
> > index ac28d22..f8eadd3 100644
> > --- a/src/gallium/drivers/r600/r600_shader.c
> > +++ b/src/gallium/drivers/r600/r600_shader.c
> > @@ -299,15 +299,21 @@ static unsigned r600_src_from_byte_stream(unsigned char * bytes,
> > static unsigned r600_alu_from_byte_stream(struct r600_shader_ctx *ctx,
> > unsigned char * bytes, unsigned bytes_read)
> > {
> > - unsigned src_idx;
> > + unsigned src_idx, src_num;
> > struct r600_bytecode_alu alu;
> > - unsigned src_const_reg[3];
> > + unsigned src_use_sel[3];
> > + unsigned src_sel[3] = {};
> > uint32_t word0, word1;
> > -
> > +
> > + src_num = bytes[bytes_read++];
> > +
> > memset(&alu, 0, sizeof(alu));
> > - for(src_idx = 0; src_idx < 3; src_idx++) {
> > + for(src_idx = 0; src_idx < src_num; src_idx++) {
> > unsigned i;
> > - src_const_reg[src_idx] = bytes[bytes_read++];
> > + src_use_sel[src_idx] = bytes[bytes_read++];
> > + for (i = 0; i < 4; i++) {
> > + src_sel[src_idx] |= bytes[bytes_read++] << (i * 8);
> > + }
> > for (i = 0; i < 4; i++) {
> > alu.src[src_idx].value |= bytes[bytes_read++] << (i * 8);
> > }
> > @@ -327,9 +333,22 @@ static unsigned r600_alu_from_byte_stream(struct r600_shader_ctx *ctx,
> > break;
> > }
> >
> > - for(src_idx = 0; src_idx < 3; src_idx++) {
> > - if (src_const_reg[src_idx])
> > - alu.src[src_idx].sel += 512;
> > + for(src_idx = 0; src_idx < src_num; src_idx++) {
> > + if (src_use_sel[src_idx]) {
> > + unsigned sel = src_sel[src_idx];
> > +
> > + alu.src[src_idx].chan = sel & 3;
> > + sel >>= 2;
> > +
> > + if (sel>=512) { /* constant */
> > + sel -= 512;
> > + alu.src[src_idx].kc_bank = sel >> 12;
> > + alu.src[src_idx].sel = (sel & 4095) + 512;
> > + }
> > + else {
> > + alu.src[src_idx].sel = sel;
> > + }
> > + }
> > }
> >
> > #if HAVE_LLVM < 0x0302
> > @@ -503,7 +522,7 @@ static int r600_vtx_from_byte_stream(struct r600_shader_ctx *ctx,
> > fprintf(stderr, "Error adding vtx\n");
> > }
> > /* Use the Texture Cache */
> > - ctx->bc->cf_last->inst = EG_V_SQ_CF_WORD1_SQ_CF_INST_TEX;
> > + ctx->bc->cf_last->inst = V_SQ_CF_WORD1_SQ_CF_INST_VTX;
> > return bytes_read;
> > }
> >
> > @@ -1239,7 +1258,7 @@ static int r600_shader_from_tgsi(struct r600_screen *rscreen,
> > }
> >
> > #ifdef R600_USE_LLVM
> > - if (use_llvm && ctx.info.indirect_files) {
> > + if (use_llvm && ctx.info.indirect_files && (ctx.info.indirect_files & (1 << TGSI_FILE_CONSTANT)) != ctx.info.indirect_files) {
> > fprintf(stderr, "Warning: R600 LLVM backend does not support "
> > "indirect adressing. Falling back to TGSI "
> > "backend.\n");
> > diff --git a/src/gallium/drivers/radeon/radeon_setup_tgsi_llvm.c b/src/gallium/drivers/radeon/radeon_setup_tgsi_llvm.c
> > index 9cb0e9a..83c962f 100644
> > --- a/src/gallium/drivers/radeon/radeon_setup_tgsi_llvm.c
> > +++ b/src/gallium/drivers/radeon/radeon_setup_tgsi_llvm.c
> > @@ -324,6 +324,10 @@ emit_store(
> > }
> >
> > switch(reg->Register.File) {
> > + case TGSI_FILE_ADDRESS:
> > + temp_ptr = bld->addr[reg->Register.Index][chan_index];
> > + LLVMBuildStore(builder, value, temp_ptr);
> > + continue;
> > case TGSI_FILE_OUTPUT:
> > temp_ptr = bld->outputs[reg->Register.Index][chan_index];
> > break;
> > --
> > 1.8.0.1
> >
> > _______________________________________________
> > mesa-dev mailing list
> > mesa-dev at lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/mesa-dev
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