[Mesa-dev] [PATCH] glsl: use a separate div_to_mul_rcp lowering flag for integers

[Bryan Cain]

TGSI, at the very least, has UDIV/IDIV instructions for integer division.
---
 src/glsl/ir_optimization.h                 |   13 +++++++------
 src/glsl/lower_instructions.cpp            |    4 +++-
 src/mesa/drivers/dri/i965/brw_shader.cpp   |    1 +
 src/mesa/program/ir_to_mesa.cpp            |    2 +-
 src/mesa/state_tracker/st_glsl_to_tgsi.cpp |    2 +-
 5 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/src/glsl/ir_optimization.h b/src/glsl/ir_optimization.h
index f7808bd..48448d4 100644
--- a/src/glsl/ir_optimization.h
+++ b/src/glsl/ir_optimization.h
@@ -29,12 +29,13 @@
  */
 
 /* Operations for lower_instructions() */
-#define SUB_TO_ADD_NEG 0x01
-#define DIV_TO_MUL_RCP 0x02
-#define EXP_TO_EXP2    0x04
-#define POW_TO_EXP2    0x08
-#define LOG_TO_LOG2    0x10
-#define MOD_TO_FRACT   0x20
+#define SUB_TO_ADD_NEG     0x01
+#define DIV_TO_MUL_RCP     0x02
+#define EXP_TO_EXP2        0x04
+#define POW_TO_EXP2        0x08
+#define LOG_TO_LOG2        0x10
+#define MOD_TO_FRACT       0x20
+#define INT_DIV_TO_MUL_RCP 0x40
 
 bool do_common_optimization(exec_list *ir, bool linked, unsigned max_unroll_iterations);
 
diff --git a/src/glsl/lower_instructions.cpp b/src/glsl/lower_instructions.cpp
index 23aa19b..fd0c760 100644
--- a/src/glsl/lower_instructions.cpp
+++ b/src/glsl/lower_instructions.cpp
@@ -265,7 +265,9 @@ lower_instructions_visitor::visit_leave(ir_expression *ir)
       break;
 
    case ir_binop_div:
-      if (lowering(DIV_TO_MUL_RCP))
+      if (lowering(INT_DIV_TO_MUL_RCP) && ir->operands[1]->type->is_integer())
+	 div_to_mul_rcp(ir);
+      else if (lowering(DIV_TO_MUL_RCP))
 	 div_to_mul_rcp(ir);
       break;
 
diff --git a/src/mesa/drivers/dri/i965/brw_shader.cpp b/src/mesa/drivers/dri/i965/brw_shader.cpp
index 3ff6bba..7e53097 100644
--- a/src/mesa/drivers/dri/i965/brw_shader.cpp
+++ b/src/mesa/drivers/dri/i965/brw_shader.cpp
@@ -100,6 +100,7 @@ brw_link_shader(struct gl_context *ctx, struct gl_shader_program *prog)
       lower_instructions(shader->ir,
 			 MOD_TO_FRACT |
 			 DIV_TO_MUL_RCP |
+			 INT_DIV_TO_MUL_RCP |
 			 SUB_TO_ADD_NEG |
 			 EXP_TO_EXP2 |
 			 LOG_TO_LOG2);
diff --git a/src/mesa/program/ir_to_mesa.cpp b/src/mesa/program/ir_to_mesa.cpp
index 6820e4c..dd154db 100644
--- a/src/mesa/program/ir_to_mesa.cpp
+++ b/src/mesa/program/ir_to_mesa.cpp
@@ -3232,7 +3232,7 @@ _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
+				 | LOG_TO_LOG2 | INT_DIV_TO_MUL_RCP
 				 | ((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 9cac309..7aef4aa 100644
--- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
+++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
@@ -5012,7 +5012,7 @@ st_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
+        			 | LOG_TO_LOG2 | INT_DIV_TO_MUL_RCP
         			 | ((options->EmitNoPow) ? POW_TO_EXP2 : 0)));
 
          progress = do_lower_jumps(ir, true, true, options->EmitNoMainReturn, options->EmitNoCont, options->EmitNoLoops) || progress;
-- 
1.7.1