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authorKenneth Graunke <[email protected]>2012-12-01 23:49:26 -0800
committerMatt Turner <[email protected]>2013-02-28 13:18:59 -0800
commit93066ce1299a7be8f670e527f249940c635605b4 (patch)
tree1e7c958b7feb9a605a6c9f482bc68798990c89f4 /src/mesa
parent18281d60889c7bb0ef14d2aa8a080cdaead7adb3 (diff)
glsl: Convert mix() to use a new ir_triop_lrp opcode.
Many GPUs have an instruction to do linear interpolation which is more efficient than simply performing the algebra necessary (two multiplies, an add, and a subtract). Pattern matching or peepholing this is more desirable, but can be tricky. By using an opcode, we can at least make shaders which use the mix() built-in get the more efficient behavior. Currently, all consumers lower ir_triop_lrp. Subsequent patches will actually generate different code. v2 [mattst88]: - Add LRP_TO_ARITH flag to ir_to_mesa.cpp. Will be removed in a subsequent patch and ir_triop_lrp translated directly. v3 [mattst88]: - Move changes from the next patch to opt_algebraic.cpp to accept 3-src operations. Reviewed-by: Matt Turner <[email protected]> Reviewed-by: Eric Anholt <[email protected]> Signed-off-by: Kenneth Graunke <[email protected]>
Diffstat (limited to 'src/mesa')
-rw-r--r--src/mesa/drivers/dri/i965/brw_shader.cpp3
-rw-r--r--src/mesa/program/ir_to_mesa.cpp6
-rw-r--r--src/mesa/state_tracker/st_glsl_to_tgsi.cpp1
3 files changed, 8 insertions, 2 deletions
diff --git a/src/mesa/drivers/dri/i965/brw_shader.cpp b/src/mesa/drivers/dri/i965/brw_shader.cpp
index c71715ee512..9ab18cc7d63 100644
--- a/src/mesa/drivers/dri/i965/brw_shader.cpp
+++ b/src/mesa/drivers/dri/i965/brw_shader.cpp
@@ -155,7 +155,8 @@ brw_link_shader(struct gl_context *ctx, struct gl_shader_program *shProg)
DIV_TO_MUL_RCP |
SUB_TO_ADD_NEG |
EXP_TO_EXP2 |
- LOG_TO_LOG2);
+ LOG_TO_LOG2 |
+ LRP_TO_ARITH);
/* Pre-gen6 HW can only nest if-statements 16 deep. Beyond this,
* if-statements need to be flattened.
diff --git a/src/mesa/program/ir_to_mesa.cpp b/src/mesa/program/ir_to_mesa.cpp
index ce409eca9d1..30305d2e77d 100644
--- a/src/mesa/program/ir_to_mesa.cpp
+++ b/src/mesa/program/ir_to_mesa.cpp
@@ -1478,6 +1478,10 @@ ir_to_mesa_visitor::visit(ir_expression *ir)
assert(!"not supported");
break;
+ case ir_triop_lrp:
+ assert(!"ir_triop_lrp should have been lowered.");
+ break;
+
case ir_quadop_vector:
/* This operation should have already been handled.
*/
@@ -2993,7 +2997,7 @@ _mesa_ir_link_shader(struct gl_context *ctx, struct gl_shader_program *prog)
/* Lowering */
do_mat_op_to_vec(ir);
lower_instructions(ir, (MOD_TO_FRACT | DIV_TO_MUL_RCP | EXP_TO_EXP2
- | LOG_TO_LOG2 | INT_DIV_TO_MUL_RCP
+ | LOG_TO_LOG2 | INT_DIV_TO_MUL_RCP | LRP_TO_ARITH
| ((options->EmitNoPow) ? POW_TO_EXP2 : 0)));
progress = do_lower_jumps(ir, true, true, options->EmitNoMainReturn, options->EmitNoCont, options->EmitNoLoops) || progress;
diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
index 63b74285aa3..757bd71aaba 100644
--- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
+++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
@@ -5189,6 +5189,7 @@ st_link_shader(struct gl_context *ctx, struct gl_shader_program *prog)
DIV_TO_MUL_RCP |
EXP_TO_EXP2 |
LOG_TO_LOG2 |
+ LRP_TO_ARITH |
(options->EmitNoPow ? POW_TO_EXP2 : 0) |
(!ctx->Const.NativeIntegers ? INT_DIV_TO_MUL_RCP : 0));