[Mesa-dev] [PATCH 2/2] i965: Prevent implicit upcasts to brw_reg.

Matt Turner mattst88 at gmail.com
Thu Nov 19 22:40:53 PST 2015


Now that backend_reg inherits from brw_reg, we have to be careful to
avoid the object slicing problem.
---
 src/mesa/drivers/dri/i965/brw_fs.cpp               |  6 +++--
 .../drivers/dri/i965/brw_fs_copy_propagation.cpp   |  4 +--
 src/mesa/drivers/dri/i965/brw_fs_generator.cpp     |  2 +-
 src/mesa/drivers/dri/i965/brw_shader.h             | 31 +++++++++++++++++++++-
 src/mesa/drivers/dri/i965/brw_vec4.cpp             | 15 ++++++-----
 .../drivers/dri/i965/brw_vec4_copy_propagation.cpp |  4 +--
 src/mesa/drivers/dri/i965/brw_vec4_generator.cpp   | 10 +++----
 7 files changed, 53 insertions(+), 19 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index e9c990d..a5f1d8f 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -392,7 +392,8 @@ fs_reg::fs_reg(struct brw_reg reg) :
 bool
 fs_reg::equals(const fs_reg &r) const
 {
-   return (memcmp((brw_reg *)this, (brw_reg *)&r, sizeof(brw_reg)) == 0 &&
+   return (memcmp(&this->as_brw_reg(), &r.as_brw_reg(),
+                  sizeof(struct brw_reg)) == 0 &&
            reg_offset == r.reg_offset &&
            subreg_offset == r.subreg_offset &&
            !reladdr && !r.reladdr &&
@@ -2037,7 +2038,8 @@ fs_visitor::opt_algebraic()
             if (inst->dst.type != inst->src[0].type)
                assert(!"unimplemented: saturate mixed types");
 
-            if (brw_saturate_immediate(inst->dst.type, &inst->src[0])) {
+            if (brw_saturate_immediate(inst->dst.type,
+                                       &inst->src[0].as_brw_reg())) {
                inst->saturate = false;
                progress = true;
             }
diff --git a/src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp b/src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp
index 426ea57..b72fe33 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp
@@ -478,14 +478,14 @@ fs_visitor::try_constant_propagate(fs_inst *inst, acp_entry *entry)
 
       if (inst->src[i].abs) {
          if ((devinfo->gen >= 8 && is_logic_op(inst->opcode)) ||
-             !brw_abs_immediate(val.type, &val)) {
+             !brw_abs_immediate(val.type, &val.as_brw_reg())) {
             continue;
          }
       }
 
       if (inst->src[i].negate) {
          if ((devinfo->gen >= 8 && is_logic_op(inst->opcode)) ||
-             !brw_negate_immediate(val.type, &val)) {
+             !brw_negate_immediate(val.type, &val.as_brw_reg())) {
             continue;
          }
       }
diff --git a/src/mesa/drivers/dri/i965/brw_fs_generator.cpp b/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
index 77969c4..ea37ea4 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
@@ -92,7 +92,7 @@ brw_reg_from_fs_reg(fs_inst *inst, fs_reg *reg, unsigned gen)
    case ARF:
    case FIXED_GRF:
    case IMM:
-      brw_reg = *static_cast<struct brw_reg *>(reg);
+      brw_reg = reg->as_brw_reg();
       break;
    case BAD_FILE:
       /* Probably unused. */
diff --git a/src/mesa/drivers/dri/i965/brw_shader.h b/src/mesa/drivers/dri/i965/brw_shader.h
index a4139cf..52b9aff 100644
--- a/src/mesa/drivers/dri/i965/brw_shader.h
+++ b/src/mesa/drivers/dri/i965/brw_shader.h
@@ -39,11 +39,21 @@
 #define MAX_VGRF_SIZE 16
 
 #ifdef __cplusplus
-struct backend_reg : public brw_reg
+struct backend_reg : private brw_reg
 {
    backend_reg() {}
    backend_reg(struct brw_reg reg) : brw_reg(reg) {}
 
+   const brw_reg &as_brw_reg() const
+   {
+      return static_cast<const brw_reg &>(*this);
+   }
+
+   brw_reg &as_brw_reg()
+   {
+      return static_cast<brw_reg &>(*this);
+   }
+
    bool is_zero() const;
    bool is_one() const;
    bool is_negative_one() const;
@@ -61,6 +71,25 @@ struct backend_reg : public brw_reg
     * For uniforms, this is in units of 1 float.
     */
    uint16_t reg_offset;
+
+   using brw_reg::type;
+   using brw_reg::file;
+   using brw_reg::negate;
+   using brw_reg::abs;
+   using brw_reg::address_mode;
+   using brw_reg::subnr;
+   using brw_reg::nr;
+
+   using brw_reg::swizzle;
+   using brw_reg::writemask;
+   using brw_reg::indirect_offset;
+   using brw_reg::vstride;
+   using brw_reg::width;
+   using brw_reg::hstride;
+
+   using brw_reg::f;
+   using brw_reg::d;
+   using brw_reg::ud;
 };
 #endif
 
diff --git a/src/mesa/drivers/dri/i965/brw_vec4.cpp b/src/mesa/drivers/dri/i965/brw_vec4.cpp
index 44893e3..f564ce1 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4.cpp
@@ -79,7 +79,7 @@ src_reg::src_reg(struct brw_reg reg) :
 }
 
 src_reg::src_reg(const dst_reg &reg) :
-   backend_reg(static_cast<struct brw_reg>(reg))
+   backend_reg(reg.as_brw_reg())
 {
    this->reg_offset = reg.reg_offset;
    this->reladdr = reg.reladdr;
@@ -137,7 +137,7 @@ dst_reg::dst_reg(struct brw_reg reg) :
 }
 
 dst_reg::dst_reg(const src_reg &reg) :
-   backend_reg(static_cast<struct brw_reg>(reg))
+   backend_reg(reg.as_brw_reg())
 {
    this->reg_offset = reg.reg_offset;
    this->writemask = brw_mask_for_swizzle(reg.swizzle);
@@ -147,7 +147,8 @@ dst_reg::dst_reg(const src_reg &reg) :
 bool
 dst_reg::equals(const dst_reg &r) const
 {
-   return (memcmp((brw_reg *)this, (brw_reg *)&r, sizeof(brw_reg)) == 0 &&
+   return (memcmp(&this->as_brw_reg(), &r.as_brw_reg(),
+                  sizeof(struct brw_reg)) == 0 &&
            reg_offset == r.reg_offset &&
            (reladdr == r.reladdr ||
             (reladdr && r.reladdr && reladdr->equals(*r.reladdr))));
@@ -285,7 +286,8 @@ vec4_visitor::implied_mrf_writes(vec4_instruction *inst)
 bool
 src_reg::equals(const src_reg &r) const
 {
-   return (memcmp((brw_reg *)this, (brw_reg *)&r, sizeof(brw_reg)) == 0 &&
+   return (memcmp(&this->as_brw_reg(), &r.as_brw_reg(),
+                  sizeof(struct brw_reg)) == 0 &&
 	   reg_offset == r.reg_offset &&
 	   !reladdr && !r.reladdr);
 }
@@ -587,7 +589,8 @@ vec4_visitor::opt_algebraic()
             if (inst->dst.type != inst->src[0].type)
                assert(!"unimplemented: saturate mixed types");
 
-            if (brw_saturate_immediate(inst->dst.type, &inst->src[0])) {
+            if (brw_saturate_immediate(inst->dst.type,
+                                       &inst->src[0].as_brw_reg())) {
                inst->saturate = false;
                progress = true;
             }
@@ -1769,7 +1772,7 @@ vec4_visitor::convert_to_hw_regs()
 
       case ARF:
       case FIXED_GRF:
-         reg = dst;
+         reg = dst.as_brw_reg();
          break;
 
       case BAD_FILE:
diff --git a/src/mesa/drivers/dri/i965/brw_vec4_copy_propagation.cpp b/src/mesa/drivers/dri/i965/brw_vec4_copy_propagation.cpp
index 3b76e36..ce5f7ab 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_copy_propagation.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_copy_propagation.cpp
@@ -134,14 +134,14 @@ try_constant_propagate(const struct brw_device_info *devinfo,
 
    if (inst->src[arg].abs) {
       if ((devinfo->gen >= 8 && is_logic_op(inst->opcode)) ||
-          !brw_abs_immediate(value.type, &value)) {
+          !brw_abs_immediate(value.type, &value.as_brw_reg())) {
          return false;
       }
    }
 
    if (inst->src[arg].negate) {
       if ((devinfo->gen >= 8 && is_logic_op(inst->opcode)) ||
-          !brw_negate_immediate(value.type, &value)) {
+          !brw_negate_immediate(value.type, &value.as_brw_reg())) {
          return false;
       }
    }
diff --git a/src/mesa/drivers/dri/i965/brw_vec4_generator.cpp b/src/mesa/drivers/dri/i965/brw_vec4_generator.cpp
index 20107ac..c06fb21 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_generator.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_generator.cpp
@@ -356,7 +356,7 @@ generate_gs_urb_write_allocate(struct brw_codegen *p, vec4_instruction *inst)
 
    /* We pass the temporary passed in src0 as the writeback register */
    brw_urb_WRITE(p,
-                 inst->src[0], /* dest */
+                 inst->src[0].as_brw_reg(), /* dest */
                  inst->base_mrf, /* starting mrf reg nr */
                  src,
                  BRW_URB_WRITE_ALLOCATE_COMPLETE,
@@ -369,8 +369,8 @@ generate_gs_urb_write_allocate(struct brw_codegen *p, vec4_instruction *inst)
    brw_push_insn_state(p);
    brw_set_default_access_mode(p, BRW_ALIGN_1);
    brw_set_default_mask_control(p, BRW_MASK_DISABLE);
-   brw_MOV(p, get_element_ud(inst->dst, 0),
-           get_element_ud(inst->src[0], 0));
+   brw_MOV(p, get_element_ud(inst->dst.as_brw_reg(), 0),
+           get_element_ud(inst->src[0].as_brw_reg(), 0));
    brw_pop_insn_state(p);
 }
 
@@ -1059,9 +1059,9 @@ generate_code(struct brw_codegen *p,
          annotate(p->devinfo, &annotation, cfg, inst, p->next_insn_offset);
 
       for (unsigned int i = 0; i < 3; i++) {
-         src[i] = inst->src[i];
+         src[i] = inst->src[i].as_brw_reg();
       }
-      dst = inst->dst;
+      dst = inst->dst.as_brw_reg();
 
       brw_set_default_predicate_control(p, inst->predicate);
       brw_set_default_predicate_inverse(p, inst->predicate_inverse);
-- 
2.4.9



More information about the mesa-dev mailing list