[Mesa-dev] [PATCH 3/6] i965/vec4: Add support for SHADER_OPCODE_MOV_INDIRECT

[Jason Ekstrand]

---
 src/mesa/drivers/dri/i965/brw_vec4.cpp           |  1 +
 src/mesa/drivers/dri/i965/brw_vec4_generator.cpp | 67 ++++++++++++++++++++++++
 2 files changed, 68 insertions(+)

diff --git a/src/mesa/drivers/dri/i965/brw_vec4.cpp b/src/mesa/drivers/dri/i965/brw_vec4.cpp
index 87b5ff9..e2aa109 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4.cpp
@@ -251,6 +251,7 @@ vec4_instruction::can_do_writemask(const struct brw_device_info *devinfo)
    case TES_OPCODE_CREATE_INPUT_READ_HEADER:
    case TES_OPCODE_ADD_INDIRECT_URB_OFFSET:
    case VEC4_OPCODE_URB_READ:
+   case SHADER_OPCODE_MOV_INDIRECT:
       return false;
    default:
       /* The MATH instruction on Gen6 only executes in align1 mode, which does
diff --git a/src/mesa/drivers/dri/i965/brw_vec4_generator.cpp b/src/mesa/drivers/dri/i965/brw_vec4_generator.cpp
index 8409e82..4b44c3a 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_generator.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_generator.cpp
@@ -1399,6 +1399,69 @@ generate_set_simd4x2_header_gen9(struct brw_codegen *p,
 }
 
 static void
+generate_mov_indirect(struct brw_codegen *p,
+                      vec4_instruction *inst,
+                      struct brw_reg dst, struct brw_reg reg,
+                      struct brw_reg indirect, struct brw_reg length)
+{
+   assert(indirect.type == BRW_REGISTER_TYPE_UD);
+   assert(p->devinfo->gen >= 6);
+
+   unsigned imm_byte_offset = reg.nr * REG_SIZE + reg.subnr * (REG_SIZE / 2);
+
+   /* This instruction acts in align1 mode */
+   assert(dst.writemask == WRITEMASK_XYZW);
+
+   if (indirect.file == BRW_IMMEDIATE_VALUE) {
+      imm_byte_offset += indirect.ud;
+
+      reg.nr = imm_byte_offset / REG_SIZE;
+      reg.subnr = (imm_byte_offset / (REG_SIZE / 2)) % 2;
+      unsigned shift = (imm_byte_offset / 4) % 4;
+      reg.swizzle += BRW_SWIZZLE4(shift, shift, shift, shift);
+
+      brw_MOV(p, dst, reg);
+   } else {
+      brw_push_insn_state(p);
+      brw_set_default_access_mode(p, BRW_ALIGN_1);
+      brw_set_default_mask_control(p, BRW_MASK_DISABLE);
+
+      struct brw_reg addr = vec8(brw_address_reg(0));
+
+      /* We need to move the indirect value into the address register.  In
+       * order to make things make some sense, we want to respect at least the
+       * X component of the swizzle.  In order to do that, we need to convert
+       * the subnr (probably 0) to an align1 subnr and add in the swizzle.
+       */
+      assert(brw_is_single_value_swizzle(indirect.swizzle));
+      indirect.subnr = (indirect.subnr * 4 + BRW_GET_SWZ(indirect.swizzle, 0));
+
+      /* We then use a region of <8,4,0>:uw to pick off the first 2 bytes of
+       * the indirect and splat it out to all four channels of the given half
+       * of a0.
+       */
+      indirect.subnr *= 2;
+      indirect = stride(retype(indirect, BRW_REGISTER_TYPE_UW), 8, 4, 0);
+      brw_ADD(p, addr, indirect, brw_imm_uw(imm_byte_offset));
+
+      /* Now we need to incorporate the swizzle from the source register */
+      if (reg.swizzle != BRW_SWIZZLE_XXXX) {
+         uint32_t uv_swiz = BRW_GET_SWZ(reg.swizzle, 0) << 2 |
+                            BRW_GET_SWZ(reg.swizzle, 1) << 6 |
+                            BRW_GET_SWZ(reg.swizzle, 2) << 10 |
+                            BRW_GET_SWZ(reg.swizzle, 3) << 14;
+         uv_swiz |= uv_swiz << 16;
+
+         brw_ADD(p, addr, addr, brw_imm_uv(uv_swiz));
+      }
+
+      brw_MOV(p, dst, retype(brw_VxH_indirect(0, 0), reg.type));
+
+      brw_pop_insn_state(p);
+   }
+}
+
+static void
 generate_code(struct brw_codegen *p,
               const struct brw_compiler *compiler,
               void *log_data,
@@ -1946,6 +2009,10 @@ generate_code(struct brw_codegen *p,
          brw_WAIT(p);
          break;
 
+      case SHADER_OPCODE_MOV_INDIRECT:
+         generate_mov_indirect(p, inst, dst, src[0], src[1], src[2]);
+         break;
+
       default:
          unreachable("Unsupported opcode");
       }
-- 
2.5.0.400.gff86faf