nir: Add flipping of gl_PointCoord.y in nir_lower_wpos_ytransform.

This is controlled by a new nir_shader_compiler_options flag, and fixes
dEQP-GLES3.functional.shaders.builtin_variable.pointcoord on V3D.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
This commit is contained in:
Eric Anholt 2018-07-06 13:43:06 -07:00
parent b5a56a11da
commit d934d3206e
3 changed files with 33 additions and 0 deletions

View file

@ -1927,6 +1927,7 @@ const nir_shader_compiler_options v3d_nir_options = {
.lower_ifind_msb = true,
.lower_ldexp = true,
.lower_mul_high = true,
.lower_wpos_pntc = true,
.native_integers = true,
};

View file

@ -2024,6 +2024,9 @@ typedef struct nir_shader_compiler_options {
bool lower_device_index_to_zero;
/* Set if nir_lower_wpos_ytransform() should also invert gl_PointCoord. */
bool lower_wpos_pntc;
/**
* Should nir_lower_io() create load_interpolated_input intrinsics?
*

View file

@ -231,6 +231,31 @@ lower_fragcoord(lower_wpos_ytransform_state *state,
emit_wpos_adjustment(state, intr, fragcoord, invert, adjX, adjY);
}
static void
lower_load_pointcoord(lower_wpos_ytransform_state *state,
nir_intrinsic_instr *intr)
{
nir_builder *b = &state->b;
b->cursor = nir_after_instr(&intr->instr);
nir_ssa_def *pntc = &intr->dest.ssa;
nir_ssa_def *transform = get_transform(state);
nir_ssa_def *y = nir_channel(b, pntc, 1);
/* The offset is 1 if we're flipping, 0 otherwise. */
nir_ssa_def *offset = nir_fmax(b, nir_channel(b, transform, 2),
nir_imm_float(b, 0.0));
/* Flip the sign of y if we're flipping. */
nir_ssa_def *scaled = nir_fmul(b, y, nir_channel(b, transform, 0));
/* Reassemble the vector. */
nir_ssa_def *flipped_pntc = nir_vec2(b,
nir_channel(b, pntc, 0),
nir_fadd(b, offset, scaled));
nir_ssa_def_rewrite_uses_after(&intr->dest.ssa, nir_src_for_ssa(flipped_pntc),
flipped_pntc->parent_instr);
}
/* turns 'fddy(p)' into 'fddy(fmul(p, transform.x))' */
static void
lower_fddy(lower_wpos_ytransform_state *state, nir_alu_instr *fddy)
@ -310,6 +335,10 @@ lower_wpos_ytransform_block(lower_wpos_ytransform_state *state, nir_block *block
} else if (var->data.mode == nir_var_system_value &&
var->data.location == SYSTEM_VALUE_SAMPLE_POS) {
lower_load_sample_pos(state, intr);
} else if (var->data.mode == nir_var_shader_in &&
var->data.location == VARYING_SLOT_PNTC &&
state->shader->options->lower_wpos_pntc) {
lower_load_pointcoord(state, intr);
}
} else if (intr->intrinsic == nir_intrinsic_load_frag_coord) {
lower_fragcoord(state, intr, NULL);