Mesa (master): gallivm: Avoid control flow for two-sided stencil test.
Jose Fonseca
jrfonseca at kemper.freedesktop.org
Fri Oct 8 16:44:40 UTC 2010
Module: Mesa
Branch: master
Commit: d5ef59d8b0ce2ea8f0ad983951e696d1679e3eb7
URL: http://cgit.freedesktop.org/mesa/mesa/commit/?id=d5ef59d8b0ce2ea8f0ad983951e696d1679e3eb7
Author: José Fonseca <jfonseca at vmware.com>
Date: Fri Oct 8 16:56:45 2010 +0100
gallivm: Avoid control flow for two-sided stencil test.
---
src/gallium/drivers/llvmpipe/lp_bld_depth.c | 150 ++++++++++----------------
1 files changed, 58 insertions(+), 92 deletions(-)
diff --git a/src/gallium/drivers/llvmpipe/lp_bld_depth.c b/src/gallium/drivers/llvmpipe/lp_bld_depth.c
index 7561899..7eabe05 100644
--- a/src/gallium/drivers/llvmpipe/lp_bld_depth.c
+++ b/src/gallium/drivers/llvmpipe/lp_bld_depth.c
@@ -128,57 +128,32 @@ lp_build_stencil_test_single(struct lp_build_context *bld,
/**
* Do the one or two-sided stencil test comparison.
* \sa lp_build_stencil_test_single
- * \param face an integer indicating front (+) or back (-) facing polygon.
- * If NULL, assume front-facing.
+ * \param front_facing an integer vector mask, indicating front (~0) or back
+ * (0) facing polygon. If NULL, assume front-facing.
*/
static LLVMValueRef
lp_build_stencil_test(struct lp_build_context *bld,
const struct pipe_stencil_state stencil[2],
LLVMValueRef stencilRefs[2],
LLVMValueRef stencilVals,
- LLVMValueRef face)
+ LLVMValueRef front_facing)
{
LLVMValueRef res;
assert(stencil[0].enabled);
- if (stencil[1].enabled && face) {
- /* do two-sided test */
- struct lp_build_flow_context *flow_ctx;
- struct lp_build_if_state if_ctx;
- LLVMValueRef front_facing;
- LLVMValueRef zero = LLVMConstReal(LLVMFloatType(), 0.0);
- LLVMValueRef result = bld->undef;
+ /* do front face test */
+ res = lp_build_stencil_test_single(bld, &stencil[0],
+ stencilRefs[0], stencilVals);
- flow_ctx = lp_build_flow_create(bld->builder);
- lp_build_flow_scope_begin(flow_ctx);
+ if (stencil[1].enabled && front_facing) {
+ /* do back face test */
+ LLVMValueRef back_res;
- lp_build_flow_scope_declare(flow_ctx, &result);
+ back_res = lp_build_stencil_test_single(bld, &stencil[1],
+ stencilRefs[1], stencilVals);
- /* front_facing = face > 0.0 */
- front_facing = LLVMBuildFCmp(bld->builder, LLVMRealUGT, face, zero, "");
-
- lp_build_if(&if_ctx, flow_ctx, bld->builder, front_facing);
- {
- result = lp_build_stencil_test_single(bld, &stencil[0],
- stencilRefs[0], stencilVals);
- }
- lp_build_else(&if_ctx);
- {
- result = lp_build_stencil_test_single(bld, &stencil[1],
- stencilRefs[1], stencilVals);
- }
- lp_build_endif(&if_ctx);
-
- lp_build_flow_scope_end(flow_ctx);
- lp_build_flow_destroy(flow_ctx);
-
- res = result;
- }
- else {
- /* do single-side test */
- res = lp_build_stencil_test_single(bld, &stencil[0],
- stencilRefs[0], stencilVals);
+ res = lp_build_select(bld, front_facing, res, back_res);
}
return res;
@@ -195,14 +170,12 @@ lp_build_stencil_op_single(struct lp_build_context *bld,
const struct pipe_stencil_state *stencil,
enum stencil_op op,
LLVMValueRef stencilRef,
- LLVMValueRef stencilVals,
- LLVMValueRef mask)
+ LLVMValueRef stencilVals)
{
- const unsigned stencilMax = 255; /* XXX fix */
struct lp_type type = bld->type;
LLVMValueRef res;
- LLVMValueRef max = lp_build_const_int_vec(type, stencilMax);
+ LLVMValueRef max = lp_build_const_int_vec(type, 0xff);
unsigned stencil_op;
assert(type.sign);
@@ -255,19 +228,7 @@ lp_build_stencil_op_single(struct lp_build_context *bld,
break;
default:
assert(0 && "bad stencil op mode");
- res = NULL;
- }
-
- if (stencil->writemask != stencilMax) {
- /* mask &= stencil->writemask */
- LLVMValueRef writemask = lp_build_const_int_vec(type, stencil->writemask);
- mask = LLVMBuildAnd(bld->builder, mask, writemask, "");
- /* res = (res & mask) | (stencilVals & ~mask) */
- res = lp_build_select_bitwise(bld, writemask, res, stencilVals);
- }
- else {
- /* res = mask ? res : stencilVals */
- res = lp_build_select(bld, mask, res, stencilVals);
+ res = bld->undef;
}
return res;
@@ -284,49 +245,40 @@ lp_build_stencil_op(struct lp_build_context *bld,
LLVMValueRef stencilRefs[2],
LLVMValueRef stencilVals,
LLVMValueRef mask,
- LLVMValueRef face)
+ LLVMValueRef front_facing)
{
- assert(stencil[0].enabled);
+ LLVMValueRef res;
- if (stencil[1].enabled && face) {
- /* do two-sided op */
- struct lp_build_flow_context *flow_ctx;
- struct lp_build_if_state if_ctx;
- LLVMValueRef front_facing;
- LLVMValueRef zero = LLVMConstReal(LLVMFloatType(), 0.0);
- LLVMValueRef result = bld->undef;
+ assert(stencil[0].enabled);
- flow_ctx = lp_build_flow_create(bld->builder);
- lp_build_flow_scope_begin(flow_ctx);
+ /* do front face op */
+ res = lp_build_stencil_op_single(bld, &stencil[0], op,
+ stencilRefs[0], stencilVals);
- lp_build_flow_scope_declare(flow_ctx, &result);
+ if (stencil[1].enabled && front_facing) {
+ /* do back face op */
+ LLVMValueRef back_res;
- /* front_facing = face > 0.0 */
- front_facing = LLVMBuildFCmp(bld->builder, LLVMRealUGT, face, zero, "");
+ back_res = lp_build_stencil_op_single(bld, &stencil[1], op,
+ stencilRefs[1], stencilVals);
- lp_build_if(&if_ctx, flow_ctx, bld->builder, front_facing);
- {
- result = lp_build_stencil_op_single(bld, &stencil[0], op,
- stencilRefs[0], stencilVals, mask);
- }
- lp_build_else(&if_ctx);
- {
- result = lp_build_stencil_op_single(bld, &stencil[1], op,
- stencilRefs[1], stencilVals, mask);
- }
- lp_build_endif(&if_ctx);
-
- lp_build_flow_scope_end(flow_ctx);
- lp_build_flow_destroy(flow_ctx);
+ res = lp_build_select(bld, front_facing, res, back_res);
+ }
- return result;
+ if (stencil->writemask != 0xff) {
+ /* mask &= stencil->writemask */
+ LLVMValueRef writemask = lp_build_const_int_vec(bld->type, stencil->writemask);
+ mask = LLVMBuildAnd(bld->builder, mask, writemask, "");
+ /* res = (res & mask) | (stencilVals & ~mask) */
+ res = lp_build_select_bitwise(bld, writemask, res, stencilVals);
}
else {
- /* do single-sided op */
- return lp_build_stencil_op_single(bld, &stencil[0], op,
- stencilRefs[0], stencilVals, mask);
+ /* res = mask ? res : stencilVals */
+ res = lp_build_select(bld, mask, res, stencilVals);
}
+
+ return res;
}
@@ -519,6 +471,7 @@ lp_build_depth_stencil_test(LLVMBuilderRef builder,
LLVMValueRef z_bitmask = NULL, stencil_shift = NULL;
LLVMValueRef z_pass = NULL, s_pass_mask = NULL;
LLVMValueRef orig_mask = mask->value;
+ LLVMValueRef front_facing = NULL;
/* Sanity checking */
{
@@ -616,21 +569,34 @@ lp_build_depth_stencil_test(LLVMBuilderRef builder,
}
}
-
if (stencil[0].enabled) {
+
+ if (face) {
+ LLVMValueRef zero = LLVMConstReal(LLVMFloatType(), 0.0);
+
+ /* front_facing = face > 0.0 ? ~0 : 0 */
+ front_facing = LLVMBuildFCmp(builder, LLVMRealUGT, face, zero, "");
+ front_facing = LLVMBuildSExt(builder, front_facing,
+ LLVMIntType(bld.type.length*bld.type.width),
+ "");
+ front_facing = LLVMBuildBitCast(builder, front_facing,
+ bld.int_vec_type, "");
+ }
+
/* convert scalar stencil refs into vectors */
stencil_refs[0] = lp_build_broadcast_scalar(&bld, stencil_refs[0]);
stencil_refs[1] = lp_build_broadcast_scalar(&bld, stencil_refs[1]);
s_pass_mask = lp_build_stencil_test(&sbld, stencil,
- stencil_refs, stencil_vals, face);
+ stencil_refs, stencil_vals,
+ front_facing);
/* apply stencil-fail operator */
{
LLVMValueRef s_fail_mask = lp_build_andnot(&bld, orig_mask, s_pass_mask);
stencil_vals = lp_build_stencil_op(&sbld, stencil, S_FAIL_OP,
stencil_refs, stencil_vals,
- s_fail_mask, face);
+ s_fail_mask, front_facing);
}
}
@@ -676,13 +642,13 @@ lp_build_depth_stencil_test(LLVMBuilderRef builder,
z_fail_mask = lp_build_andnot(&bld, orig_mask, z_pass);
stencil_vals = lp_build_stencil_op(&sbld, stencil, Z_FAIL_OP,
stencil_refs, stencil_vals,
- z_fail_mask, face);
+ z_fail_mask, front_facing);
/* apply Z-pass operator */
z_pass_mask = LLVMBuildAnd(bld.builder, orig_mask, z_pass, "");
stencil_vals = lp_build_stencil_op(&sbld, stencil, Z_PASS_OP,
stencil_refs, stencil_vals,
- z_pass_mask, face);
+ z_pass_mask, front_facing);
}
}
else {
@@ -692,7 +658,7 @@ lp_build_depth_stencil_test(LLVMBuilderRef builder,
s_pass_mask = LLVMBuildAnd(bld.builder, orig_mask, s_pass_mask, "");
stencil_vals = lp_build_stencil_op(&sbld, stencil, Z_PASS_OP,
stencil_refs, stencil_vals,
- s_pass_mask, face);
+ s_pass_mask, front_facing);
}
/* The Z bits are already in the right place but we may need to shift the
More information about the mesa-commit
mailing list