i965: Use ~0 to represent true on Gen >= 6.

total instructions in shared programs: 4292303 -> 4288650 (-0.09%)
instructions in affected programs:     299670 -> 296017 (-1.22%)

Reviewed-by: Anuj Phogat <[email protected]>

4 files changed, 102 insertions, 34 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_context.c b/src/mesa/drivers/dri/i965/brw_context.c
index 12f898abdb5..216b788a7ee 100644
--- a/src/mesa/drivers/dri/i965/brw_context.c
+++ b/src/mesa/drivers/dri/i965/brw_context.c
@@ -483,7 +483,32 @@ brw_initialize_context_constants(struct brw_context *brw)
       ctx->Const.QuadsFollowProvokingVertexConvention = false;
 
    ctx->Const.NativeIntegers = true;
-   ctx->Const.UniformBooleanTrue = 1;
+
+   /* Regarding the CMP instruction, the Ivybridge PRM says:
+    *
+    *   "For each enabled channel 0b or 1b is assigned to the appropriate flag
+    *    bit and 0/all zeros or all ones (e.g, byte 0xFF, word 0xFFFF, DWord
+    *    0xFFFFFFFF) is assigned to dst."
+    *
+    * but PRMs for earlier generations say
+    *
+    *   "In dword format, one GRF may store up to 8 results. When the register
+    *    is used later as a vector of Booleans, as only LSB at each channel
+    *    contains meaning [sic] data, software should make sure all higher bits
+    *    are masked out (e.g. by 'and-ing' an [sic] 0x01 constant)."
+    *
+    * We select the representation of a true boolean uniform to match what the
+    * CMP instruction returns.
+    *
+    * The Sandybridge BSpec's description of the CMP instruction matches that
+    * of the Ivybridge PRM. (The description in the Sandybridge PRM is seems
+    * to have not been updated from Ironlake). Its CMP instruction behaves like
+    * Ivybridge and newer.
+    */
+   if (brw->gen >= 6)
+      ctx->Const.UniformBooleanTrue = ~0;
+   else
+      ctx->Const.UniformBooleanTrue = 1;
 
    /* From the gen4 PRM, volume 4 page 127:
     *
diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index f1d3fb8ec67..935cbfa0973 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -1190,11 +1190,11 @@ fs_visitor::emit_frontfacing_interpolation(ir_variable *ir)
 
    /* The frontfacing comes in as a bit in the thread payload. */
    if (brw->gen >= 6) {
-      emit(BRW_OPCODE_ASR, *reg,
+      emit(BRW_OPCODE_SHL, *reg,
 	   fs_reg(retype(brw_vec1_grf(0, 0), BRW_REGISTER_TYPE_D)),
-	   fs_reg(15));
+           fs_reg(16));
       emit(BRW_OPCODE_NOT, *reg, *reg);
-      emit(BRW_OPCODE_AND, *reg, *reg, fs_reg(1));
+      emit(BRW_OPCODE_ASR, *reg, *reg, fs_reg(31));
    } else {
       struct brw_reg r1_6ud = retype(brw_vec1_grf(1, 6), BRW_REGISTER_TYPE_UD);
       /* bit 31 is "primitive is back face", so checking < (1 << 31) gives
diff --git a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
index fa2c2269356..f2c22bbc4cf 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
@@ -526,10 +526,11 @@ fs_visitor::visit(ir_expression *ir)
 
    switch (ir->operation) {
    case ir_unop_logic_not:
-      /* Note that BRW_OPCODE_NOT is not appropriate here, since it is
-       * ones complement of the whole register, not just bit 0.
-       */
-      emit(XOR(this->result, op[0], fs_reg(1)));
+      if (ctx->Const.UniformBooleanTrue != 1) {
+         emit(NOT(this->result, op[0]));
+      } else {
+         emit(XOR(this->result, op[0], fs_reg(1)));
+      }
       break;
    case ir_unop_neg:
       op[0].negate = !op[0].negate;
@@ -697,8 +698,10 @@ fs_visitor::visit(ir_expression *ir)
    case ir_binop_all_equal:
    case ir_binop_nequal:
    case ir_binop_any_nequal:
-      resolve_bool_comparison(ir->operands[0], &op[0]);
-      resolve_bool_comparison(ir->operands[1], &op[1]);
+      if (ctx->Const.UniformBooleanTrue == 1) {
+         resolve_bool_comparison(ir->operands[0], &op[0]);
+         resolve_bool_comparison(ir->operands[1], &op[1]);
+      }
 
       emit(CMP(this->result, op[0], op[1],
                brw_conditional_for_comparison(ir->operation)));
@@ -769,9 +772,16 @@ fs_visitor::visit(ir_expression *ir)
       emit(AND(this->result, op[0], fs_reg(1)));
       break;
    case ir_unop_b2f:
-      temp = fs_reg(this, glsl_type::int_type);
-      emit(AND(temp, op[0], fs_reg(1)));
-      emit(MOV(this->result, temp));
+      if (ctx->Const.UniformBooleanTrue != 1) {
+         op[0].type = BRW_REGISTER_TYPE_UD;
+         this->result.type = BRW_REGISTER_TYPE_UD;
+         emit(AND(this->result, op[0], fs_reg(0x3f800000u)));
+         this->result.type = BRW_REGISTER_TYPE_F;
+      } else {
+         temp = fs_reg(this, glsl_type::int_type);
+         emit(AND(temp, op[0], fs_reg(1)));
+         emit(MOV(this->result, temp));
+      }
       break;
 
    case ir_unop_f2b:
@@ -2317,8 +2327,10 @@ fs_visitor::emit_bool_to_cond_code(ir_rvalue *ir)
    case ir_binop_all_equal:
    case ir_binop_nequal:
    case ir_binop_any_nequal:
-      resolve_bool_comparison(expr->operands[0], &op[0]);
-      resolve_bool_comparison(expr->operands[1], &op[1]);
+      if (ctx->Const.UniformBooleanTrue == 1) {
+         resolve_bool_comparison(expr->operands[0], &op[0]);
+         resolve_bool_comparison(expr->operands[1], &op[1]);
+      }
 
       emit(CMP(reg_null_d, op[0], op[1],
                brw_conditional_for_comparison(expr->operation)));
@@ -2379,8 +2391,10 @@ fs_visitor::emit_if_gen6(ir_if *ir)
       case ir_binop_all_equal:
       case ir_binop_nequal:
       case ir_binop_any_nequal:
-	 resolve_bool_comparison(expr->operands[0], &op[0]);
-	 resolve_bool_comparison(expr->operands[1], &op[1]);
+         if (ctx->Const.UniformBooleanTrue == 1) {
+            resolve_bool_comparison(expr->operands[0], &op[0]);
+            resolve_bool_comparison(expr->operands[1], &op[1]);
+         }
 
 	 emit(IF(op[0], op[1],
                  brw_conditional_for_comparison(expr->operation)));
@@ -3220,6 +3234,8 @@ fs_visitor::resolve_ud_negate(fs_reg *reg)
 void
 fs_visitor::resolve_bool_comparison(ir_rvalue *rvalue, fs_reg *reg)
 {
+   assert(ctx->Const.UniformBooleanTrue == 1);
+
    if (rvalue->type != glsl_type::bool_type)
       return;
 
diff --git a/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp b/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp
index cb9a1b1b68f..eca5d0cb01c 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp
@@ -1281,10 +1281,11 @@ vec4_visitor::visit(ir_expression *ir)
 
    switch (ir->operation) {
    case ir_unop_logic_not:
-      /* Note that BRW_OPCODE_NOT is not appropriate here, since it is
-       * ones complement of the whole register, not just bit 0.
-       */
-      emit(XOR(result_dst, op[0], src_reg(1)));
+      if (ctx->Const.UniformBooleanTrue != 1) {
+         emit(NOT(result_dst, op[0]));
+      } else {
+         emit(XOR(result_dst, op[0], src_reg(1)));
+      }
       break;
    case ir_unop_neg:
       op[0].negate = !op[0].negate;
@@ -1468,7 +1469,9 @@ vec4_visitor::visit(ir_expression *ir)
    case ir_binop_nequal: {
       emit(CMP(result_dst, op[0], op[1],
 	       brw_conditional_for_comparison(ir->operation)));
-      emit(AND(result_dst, result_src, src_reg(0x1)));
+      if (ctx->Const.UniformBooleanTrue == 1) {
+         emit(AND(result_dst, result_src, src_reg(1)));
+      }
       break;
    }
 
@@ -1478,11 +1481,13 @@ vec4_visitor::visit(ir_expression *ir)
 	  ir->operands[1]->type->is_vector()) {
 	 emit(CMP(dst_null_d(), op[0], op[1], BRW_CONDITIONAL_Z));
 	 emit(MOV(result_dst, src_reg(0)));
-	 inst = emit(MOV(result_dst, src_reg(1)));
+         inst = emit(MOV(result_dst, src_reg(ctx->Const.UniformBooleanTrue)));
 	 inst->predicate = BRW_PREDICATE_ALIGN16_ALL4H;
       } else {
 	 emit(CMP(result_dst, op[0], op[1], BRW_CONDITIONAL_Z));
-	 emit(AND(result_dst, result_src, src_reg(0x1)));
+         if (ctx->Const.UniformBooleanTrue == 1) {
+            emit(AND(result_dst, result_src, src_reg(1)));
+         }
       }
       break;
    case ir_binop_any_nequal:
@@ -1492,11 +1497,13 @@ vec4_visitor::visit(ir_expression *ir)
 	 emit(CMP(dst_null_d(), op[0], op[1], BRW_CONDITIONAL_NZ));
 
 	 emit(MOV(result_dst, src_reg(0)));
-	 inst = emit(MOV(result_dst, src_reg(1)));
+         inst = emit(MOV(result_dst, src_reg(ctx->Const.UniformBooleanTrue)));
 	 inst->predicate = BRW_PREDICATE_ALIGN16_ANY4H;
       } else {
 	 emit(CMP(result_dst, op[0], op[1], BRW_CONDITIONAL_NZ));
-	 emit(AND(result_dst, result_src, src_reg(0x1)));
+         if (ctx->Const.UniformBooleanTrue == 1) {
+            emit(AND(result_dst, result_src, src_reg(1)));
+         }
       }
       break;
 
@@ -1504,7 +1511,7 @@ vec4_visitor::visit(ir_expression *ir)
       emit(CMP(dst_null_d(), op[0], src_reg(0), BRW_CONDITIONAL_NZ));
       emit(MOV(result_dst, src_reg(0)));
 
-      inst = emit(MOV(result_dst, src_reg(1)));
+      inst = emit(MOV(result_dst, src_reg(ctx->Const.UniformBooleanTrue)));
       inst->predicate = BRW_PREDICATE_ALIGN16_ANY4H;
       break;
 
@@ -1553,18 +1560,34 @@ vec4_visitor::visit(ir_expression *ir)
    case ir_unop_i2u:
    case ir_unop_u2i:
    case ir_unop_u2f:
-   case ir_unop_b2f:
-   case ir_unop_b2i:
    case ir_unop_f2i:
    case ir_unop_f2u:
       emit(MOV(result_dst, op[0]));
       break;
+   case ir_unop_b2i:
+      if (ctx->Const.UniformBooleanTrue != 1) {
+         emit(AND(result_dst, op[0], src_reg(1)));
+      } else {
+         emit(MOV(result_dst, op[0]));
+      }
+      break;
+   case ir_unop_b2f:
+      if (ctx->Const.UniformBooleanTrue != 1) {
+         op[0].type = BRW_REGISTER_TYPE_UD;
+         result_dst.type = BRW_REGISTER_TYPE_UD;
+         emit(AND(result_dst, op[0], src_reg(0x3f800000u)));
+         result_dst.type = BRW_REGISTER_TYPE_F;
+      } else {
+         emit(MOV(result_dst, op[0]));
+      }
+      break;
    case ir_unop_f2b:
-   case ir_unop_i2b: {
+   case ir_unop_i2b:
       emit(CMP(result_dst, op[0], src_reg(0.0f), BRW_CONDITIONAL_NZ));
-      emit(AND(result_dst, result_src, src_reg(1)));
+      if (ctx->Const.UniformBooleanTrue == 1) {
+         emit(AND(result_dst, result_src, src_reg(1)));
+      }
       break;
-   }
 
    case ir_unop_trunc:
       emit(RNDZ(result_dst, op[0]));
@@ -1703,11 +1726,15 @@ vec4_visitor::visit(ir_expression *ir)
                                             const_offset % 16 / 4,
                                             const_offset % 16 / 4);
 
-      /* UBO bools are any nonzero int.  We store bools as either 0 or 1. */
+      /* UBO bools are any nonzero int.  We need to convert them to use the
+       * value of true stored in ctx->Const.UniformBooleanTrue.
+       */
       if (ir->type->base_type == GLSL_TYPE_BOOL) {
          emit(CMP(result_dst, packed_consts, src_reg(0u),
                   BRW_CONDITIONAL_NZ));
-         emit(AND(result_dst, result, src_reg(0x1)));
+         if (ctx->Const.UniformBooleanTrue == 1) {
+            emit(AND(result_dst, result, src_reg(1)));
+         }
       } else {
          emit(MOV(result_dst, packed_consts));
       }