Mesa (master): i965: Use implicit backend_reg copy-constructor.

[Matt Turner]

Module: Mesa
Branch: master
Commit: f093c842e65b251e24ea3a2d6daaa91326a4f862
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=f093c842e65b251e24ea3a2d6daaa91326a4f862

Author: Matt Turner <mattst88 at gmail.com>
Date:   Fri Nov 20 21:18:26 2015 -0800

i965: Use implicit backend_reg copy-constructor.

In order to do this, we have to change the signature of the
backend_reg(brw_reg) constructor to take a reference to a brw_reg in
order to avoid unresolvable ambiguity about which constructor is
actually being called in the other modifications in this patch.

As far as I understand it, the rule in C++ is that if multiple
constructors are available for parent classes, the one closest to you in
the class heirarchy is closen, but if one of them didn't take a
reference, that screws things up.

Reviewed-by: Francisco Jerez <currojerez at riseup.net>

---

 src/mesa/drivers/dri/i965/brw_shader.h |    2 +-
 src/mesa/drivers/dri/i965/brw_vec4.cpp |    6 ++----
 2 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_shader.h b/src/mesa/drivers/dri/i965/brw_shader.h
index 718a225..abf04cf 100644
--- a/src/mesa/drivers/dri/i965/brw_shader.h
+++ b/src/mesa/drivers/dri/i965/brw_shader.h
@@ -42,7 +42,7 @@
 struct backend_reg : public brw_reg
 {
    backend_reg() {}
-   backend_reg(struct brw_reg reg) : brw_reg(reg) {}
+   backend_reg(const struct brw_reg &reg) : brw_reg(reg) {}
 
    bool equals(const backend_reg &r) const;
 
diff --git a/src/mesa/drivers/dri/i965/brw_vec4.cpp b/src/mesa/drivers/dri/i965/brw_vec4.cpp
index 9f748dc..9fc0857 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4.cpp
@@ -79,9 +79,8 @@ 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)
 {
-   this->reg_offset = reg.reg_offset;
    this->reladdr = reg.reladdr;
    this->swizzle = brw_swizzle_for_mask(reg.writemask);
 }
@@ -137,9 +136,8 @@ 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)
 {
-   this->reg_offset = reg.reg_offset;
    this->writemask = brw_mask_for_swizzle(reg.swizzle);
    this->reladdr = reg.reladdr;
 }