[Mesa-dev] [PATCH v3 07/48] intel/compiler: Add some restrictions to MOV_INDIRECT and BROADCAST

[Jason Ekstrand]

These restrictions effectively already existed due to the way we use
indirect sources but weren't being directly enforced.
---
 src/intel/compiler/brw_eu_emit.c        | 16 ++++++++++++++++
 src/intel/compiler/brw_fs_generator.cpp |  2 ++
 src/intel/compiler/brw_shader.cpp       |  2 ++
 3 files changed, 20 insertions(+)

diff --git a/src/intel/compiler/brw_eu_emit.c b/src/intel/compiler/brw_eu_emit.c
index 4f0be55..e10b143 100644
--- a/src/intel/compiler/brw_eu_emit.c
+++ b/src/intel/compiler/brw_eu_emit.c
@@ -3373,6 +3373,8 @@ brw_broadcast(struct brw_codegen *p,
 
    assert(src.file == BRW_GENERAL_REGISTER_FILE &&
           src.address_mode == BRW_ADDRESS_DIRECT);
+   assert(!src.abs && !src.negate);
+   assert(src.type == dst.type);
 
    if ((src.vstride == 0 && (src.hstride == 0 || !align1)) ||
        idx.file == BRW_IMMEDIATE_VALUE) {
@@ -3385,6 +3387,20 @@ brw_broadcast(struct brw_codegen *p,
               (align1 ? stride(suboffset(src, i), 0, 1, 0) :
                stride(suboffset(src, 4 * i), 0, 4, 1)));
    } else {
+      /* From the Haswell PRM section "Register Region Restrictions":
+       *
+       *    "The lower bits of the AddressImmediate must not overflow to
+       *    change the register address.  The lower 5 bits of Address
+       *    Immediate when added to lower 5 bits of address register gives
+       *    the sub-register offset. The upper bits of Address Immediate
+       *    when added to upper bits of address register gives the register
+       *    address. Any overflow from sub-register offset is dropped."
+       *
+       * Fortunately, for broadcast, we never have a sub-register offset so
+       * this isn't an issue.
+       */
+      assert(src.subnr == 0);
+
       if (align1) {
          const struct brw_reg addr =
             retype(brw_address_reg(0), BRW_REGISTER_TYPE_UD);
diff --git a/src/intel/compiler/brw_fs_generator.cpp b/src/intel/compiler/brw_fs_generator.cpp
index 0558c82..2aa79c3 100644
--- a/src/intel/compiler/brw_fs_generator.cpp
+++ b/src/intel/compiler/brw_fs_generator.cpp
@@ -435,6 +435,8 @@ fs_generator::generate_mov_indirect(fs_inst *inst,
 {
    assert(indirect_byte_offset.type == BRW_REGISTER_TYPE_UD);
    assert(indirect_byte_offset.file == BRW_GENERAL_REGISTER_FILE);
+   assert(!reg.abs && !reg.negate);
+   assert(reg.type == dst.type);
 
    unsigned imm_byte_offset = reg.nr * REG_SIZE + reg.subnr;
 
diff --git a/src/intel/compiler/brw_shader.cpp b/src/intel/compiler/brw_shader.cpp
index 7d62479f..8f2dc3e 100644
--- a/src/intel/compiler/brw_shader.cpp
+++ b/src/intel/compiler/brw_shader.cpp
@@ -855,6 +855,8 @@ backend_instruction::can_do_source_mods() const
    case BRW_OPCODE_FBH:
    case BRW_OPCODE_FBL:
    case BRW_OPCODE_SUBB:
+   case SHADER_OPCODE_BROADCAST:
+   case SHADER_OPCODE_MOV_INDIRECT:
       return false;
    default:
       return true;
-- 
2.5.0.400.gff86faf