On Thu, Mar 05, 2015 at 05:14:09PM +0100, Marek Olšák wrote:
> Since you acked patch #3, which depends on this, I assume this has your Rb
> too?
>
No, I still want to resolved with Matt what to do about intrinsics vs
IR.
-Tom
> Marek
>
> On Mon, Mar 2, 2015 at 10:05 PM, Tom Stellard <t...@stellard.net> wrote:
> > On Mon, Mar 02, 2015 at 12:54:16PM +0100, Marek Olšák wrote:
> >> From: Marek Olšák <marek.ol...@amd.com>
> >>
> >> ---
> >> src/gallium/drivers/radeonsi/si_shader.c | 22 ++++++++++++++++------
> >> 1 file changed, 16 insertions(+), 6 deletions(-)
> >>
> >> diff --git a/src/gallium/drivers/radeonsi/si_shader.c
> >> b/src/gallium/drivers/radeonsi/si_shader.c
> >> index b0417ed..f125483 100644
> >> --- a/src/gallium/drivers/radeonsi/si_shader.c
> >> +++ b/src/gallium/drivers/radeonsi/si_shader.c
> >> @@ -192,6 +192,20 @@ static int get_param_index(unsigned semantic_name,
> >> unsigned index,
> >> }
> >>
> >> /**
> >> + * BitField Extract: ((value >> rshift) & ((1 << bitwidth) - 1))
> >> + */
> >
> > Ideally, we would just add a pattern for this in the backend and emit
> > generic
> > LLVM IR here. This would also make it possible to share the code with
> > llvmpipe.
> >
> > I think the best place to do this would be in
> > AMDGPUTargetLowering::performDAGCombine().
> >
> > -Tom
> >
> >> +static LLVMValueRef build_bfe(struct gallivm_state *gallivm,
> >> + LLVMValueRef value, LLVMValueRef rshift,
> >> + LLVMValueRef bitwidth)
> >> +{
> >> + LLVMValueRef args[3] = {value, rshift, bitwidth};
> >> +
> >> + return build_intrinsic(gallivm->builder, "llvm.AMDGPU.bfe.u32",
> >> + LLVMInt32TypeInContext(gallivm->context),
> >> + args, Elements(args), LLVMReadNoneAttribute);
> >> +}
> >> +
> >> +/**
> >> * Build an LLVM bytecode indexed load using LLVMBuildGEP + LLVMBuildLoad.
> >> * It's equivalent to doing a load from &base_ptr[index].
> >> *
> >> @@ -1721,7 +1735,6 @@ static void tex_fetch_args(
> >>
> >> /* Initialize some constants. */
> >> LLVMValueRef four = LLVMConstInt(uint_bld->elem_type, 4, 0);
> >> - LLVMValueRef F = LLVMConstInt(uint_bld->elem_type, 0xF, 0);
> >>
> >> /* Apply the formula. */
> >> LLVMValueRef fmask =
> >> @@ -1734,11 +1747,8 @@ static void tex_fetch_args(
> >> LLVMValueRef sample_index4 =
> >> LLVMBuildMul(gallivm->builder, address[sample_chan],
> >> four, "");
> >>
> >> - LLVMValueRef shifted_fmask =
> >> - LLVMBuildLShr(gallivm->builder, fmask,
> >> sample_index4, "");
> >> -
> >> - LLVMValueRef final_sample =
> >> - LLVMBuildAnd(gallivm->builder, shifted_fmask, F, "");
> >> + LLVMValueRef final_sample = build_bfe(gallivm, fmask,
> >> + sample_index4, four);
> >>
> >> /* Don't rewrite the sample index if WORD1.DATA_FORMAT of
> >> the FMASK
> >> * resource descriptor is 0 (invalid),
> >> --
> >> 2.1.0
> >>
> >> _______________________________________________
> >> mesa-dev mailing list
> >> mesa-dev@lists.freedesktop.org
> >> http://lists.freedesktop.org/mailman/listinfo/mesa-dev
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