[Mesa-dev] [PATCH 1/4] glsl: split DIV_TO_MUL_RCP into single- and double-precision flags

[Nicolai Hähnle]

From: Nicolai Hähnle <nicolai.haehnle at amd.com>

---
 src/compiler/glsl/ir_optimization.h      |  4 +++-
 src/compiler/glsl/lower_instructions.cpp | 19 +++++++++++--------
 2 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/src/compiler/glsl/ir_optimization.h b/src/compiler/glsl/ir_optimization.h
index 0d6c4e6..01e5270 100644
--- a/src/compiler/glsl/ir_optimization.h
+++ b/src/compiler/glsl/ir_optimization.h
@@ -30,7 +30,7 @@
 
 /* Operations for lower_instructions() */
 #define SUB_TO_ADD_NEG     0x01
-#define DIV_TO_MUL_RCP     0x02
+#define FDIV_TO_MUL_RCP    0x02
 #define EXP_TO_EXP2        0x04
 #define POW_TO_EXP2        0x08
 #define LOG_TO_LOG2        0x10
@@ -49,6 +49,8 @@
 #define FIND_LSB_TO_FLOAT_CAST    0x20000
 #define FIND_MSB_TO_FLOAT_CAST    0x40000
 #define IMUL_HIGH_TO_MUL          0x80000
+#define DDIV_TO_MUL_RCP           0x100000
+#define DIV_TO_MUL_RCP            (FDIV_TO_MUL_RCP | DDIV_TO_MUL_RCP)
 
 /**
  * \see class lower_packing_builtins_visitor
diff --git a/src/compiler/glsl/lower_instructions.cpp b/src/compiler/glsl/lower_instructions.cpp
index 9fc83d1..729cb13 100644
--- a/src/compiler/glsl/lower_instructions.cpp
+++ b/src/compiler/glsl/lower_instructions.cpp
@@ -54,8 +54,8 @@
  * want to recognize add(op0, neg(op1)) or the other way around to
  * produce a subtract anyway.
  *
- * DIV_TO_MUL_RCP and INT_DIV_TO_MUL_RCP:
- * --------------------------------------
+ * FDIV_TO_MUL_RCP, DDIV_TO_MUL_RCP, and INT_DIV_TO_MUL_RCP:
+ * ---------------------------------------------------------
  * Breaks an ir_binop_div expression down to op0 * (rcp(op1)).
  *
  * Many GPUs don't have a divide instruction (945 and 965 included),
@@ -63,9 +63,11 @@
  * reciprocal.  By breaking the operation down, constant reciprocals
  * can get constant folded.
  *
- * DIV_TO_MUL_RCP only lowers floating point division; INT_DIV_TO_MUL_RCP
- * handles the integer case, converting to and from floating point so that
- * RCP is possible.
+ * FDIV_TO_MUL_RCP only lowers single-precision floating point division;
+ * DDIV_TO_MUL_RCP only lowers double-precision floating point division.
+ * DIV_TO_MUL_RCP is a convenience macro that sets both flags.
+ * INT_DIV_TO_MUL_RCP handles the integer case, converting to and from floating
+ * point so that RCP is possible.
  *
  * EXP_TO_EXP2 and LOG_TO_LOG2:
  * ----------------------------
@@ -326,7 +328,8 @@ lower_instructions_visitor::mod_to_floor(ir_expression *ir)
    /* Don't generate new IR that would need to be lowered in an additional
     * pass.
     */
-   if (lowering(DIV_TO_MUL_RCP) && (ir->type->is_float() || ir->type->is_double()))
+   if ((lowering(FDIV_TO_MUL_RCP) && ir->type->is_float()) ||
+       (lowering(DDIV_TO_MUL_RCP) && ir->type->is_double()))
       div_to_mul_rcp(div_expr);
 
    ir_expression *const floor_expr =
@@ -1599,8 +1602,8 @@ lower_instructions_visitor::visit_leave(ir_expression *ir)
    case ir_binop_div:
       if (ir->operands[1]->type->is_integer() && lowering(INT_DIV_TO_MUL_RCP))
 	 int_div_to_mul_rcp(ir);
-      else if ((ir->operands[1]->type->is_float() ||
-                ir->operands[1]->type->is_double()) && lowering(DIV_TO_MUL_RCP))
+      else if ((ir->operands[1]->type->is_float() && lowering(FDIV_TO_MUL_RCP)) ||
+               (ir->operands[1]->type->is_double() && lowering(DDIV_TO_MUL_RCP)))
 	 div_to_mul_rcp(ir);
       break;
 
-- 
2.7.4