i965/fs_inst: Add an is_copy_payload helper

This commit adds a new is_copy_payload helper to fs_inst that takes the
place of the similarly named functions in cse and register coalesce.  The
two is_copy_payload functions in CSE and register coalesce were subtly
different and potentially subtly broken.  The new version unifies the two
and should be more correct.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

4 files changed, 25 insertions, 35 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index 22223e1..2a38854 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -521,6 +521,26 @@ fs_inst::is_send_from_grf() const
 }
 
 bool
+fs_inst::is_copy_payload(const brw::simple_allocator &grf_alloc) const
+{
+   if (this->opcode != SHADER_OPCODE_LOAD_PAYLOAD)
+      return false;
+
+   fs_reg reg = this->src[0];
+   if (reg.file != GRF || reg.reg_offset != 0 || reg.stride == 0)
+      return false;
+
+   if (grf_alloc.sizes[reg.reg] != this->regs_written)
+      return false;
+
+   for (int i = 1; i < this->sources; i++)
+      if (!this->src[i].equals(::offset(reg, i)))
+         return false;
+
+   return true;
+}
+
+bool
 fs_inst::can_do_source_mods(const struct brw_device_info *devinfo)
 {
    if (devinfo->gen == 6 && is_math())
diff --git a/src/mesa/drivers/dri/i965/brw_fs_cse.cpp b/src/mesa/drivers/dri/i965/brw_fs_cse.cpp
index ad38475..fc19e0f 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_cse.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_cse.cpp
@@ -43,23 +43,7 @@ struct aeb_entry : public exec_node {
 }
 
 static bool
-is_copy_payload(const fs_inst *inst)
-{
-   const int reg = inst->src[0].reg;
-   if (inst->src[0].reg_offset != 0)
-      return false;
-
-   for (int i = 1; i < inst->sources; i++) {
-      if (inst->src[i].reg != reg ||
-          inst->src[i].reg_offset != i) {
-         return false;
-      }
-   }
-   return true;
-}
-
-static bool
-is_expression(const fs_inst *const inst)
+is_expression(const fs_visitor *v, const fs_inst *const inst)
 {
    switch (inst->opcode) {
    case BRW_OPCODE_MOV:
@@ -104,7 +88,7 @@ is_expression(const fs_inst *const inst)
    case SHADER_OPCODE_COS:
       return inst->mlen < 2;
    case SHADER_OPCODE_LOAD_PAYLOAD:
-      return !is_copy_payload(inst);
+      return !inst->is_copy_payload(v->alloc);
    default:
       return inst->is_send_from_grf() && !inst->has_side_effects();
    }
@@ -219,7 +203,7 @@ fs_visitor::opt_cse_local(bblock_t *block)
    int ip = block->start_ip;
    foreach_inst_in_block(fs_inst, inst, block) {
       /* Skip some cases. */
-      if (is_expression(inst) && !inst->is_partial_write() &&
+      if (is_expression(this, inst) && !inst->is_partial_write() &&
           (inst->dst.file != HW_REG || inst->dst.is_null()))
       {
          bool found = false;
diff --git a/src/mesa/drivers/dri/i965/brw_fs_register_coalesce.cpp b/src/mesa/drivers/dri/i965/brw_fs_register_coalesce.cpp
index 09f0fad..2ad7079 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_register_coalesce.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_register_coalesce.cpp
@@ -64,21 +64,6 @@ is_nop_mov(const fs_inst *inst)
 }
 
 static bool
-is_copy_payload(const fs_visitor *v, const fs_inst *inst)
-{
-   if (v->alloc.sizes[inst->src[0].reg] != inst->regs_written)
-      return false;
-
-   fs_reg reg = inst->src[0];
-
-   for (int i = 0; i < inst->sources; i++)
-      if (!inst->src[i].equals(offset(reg, i)))
-         return false;
-
-   return true;
-}
-
-static bool
 is_coalesce_candidate(const fs_visitor *v, const fs_inst *inst)
 {
    if ((inst->opcode != BRW_OPCODE_MOV &&
@@ -99,7 +84,7 @@ is_coalesce_candidate(const fs_visitor *v, const fs_inst *inst)
       return false;
 
    if (inst->opcode == SHADER_OPCODE_LOAD_PAYLOAD) {
-      if (!is_copy_payload(v, inst)) {
+      if (!inst->is_copy_payload(v->alloc)) {
          return false;
       }
    }
diff --git a/src/mesa/drivers/dri/i965/brw_ir_fs.h b/src/mesa/drivers/dri/i965/brw_ir_fs.h
index 9ebe980..1e3d2b4 100644
--- a/src/mesa/drivers/dri/i965/brw_ir_fs.h
+++ b/src/mesa/drivers/dri/i965/brw_ir_fs.h
@@ -241,6 +241,7 @@ public:
    bool overwrites_reg(const fs_reg &reg) const;
    bool is_send_from_grf() const;
    bool is_partial_write() const;
+   bool is_copy_payload(const brw::simple_allocator &grf_alloc) const;
    int regs_read(int arg) const;
    bool can_do_source_mods(const struct brw_device_info *devinfo);
    bool has_side_effects() const;