[Mesa-dev] [PATCH v4 28/40] intel/compiler: implement is_zero, is_one, is_negative_one for 8-bit/16-bit

[Iago Toral Quiroga]

There are no 8-bit immediates, so assert in that case.
16-bit immediates are replicated in each word of a 32-bit immediate, so
we only need to check the lower 16-bits.

v2:
 - Fix is_zero with half-float to consider -0 as well (Jason).
 - Fix is_negative_one for word type.

Reviewed-by: Jason Ekstrand <jason at jlekstrand.net>
---
 src/intel/compiler/brw_shader.cpp | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/src/intel/compiler/brw_shader.cpp b/src/intel/compiler/brw_shader.cpp
index 569e68e02af..bf09c416e9e 100644
--- a/src/intel/compiler/brw_shader.cpp
+++ b/src/intel/compiler/brw_shader.cpp
@@ -719,11 +719,20 @@ backend_reg::is_zero() const
    if (file != IMM)
       return false;
 
+   assert(type_sz(type) > 1);
+
    switch (type) {
+   case BRW_REGISTER_TYPE_HF:
+      assert((d & 0xffff) == ((d >> 16) & 0xffff));
+      return (d & 0xffff) == 0 || (d & 0xffff) == 0x8000;
    case BRW_REGISTER_TYPE_F:
       return f == 0;
    case BRW_REGISTER_TYPE_DF:
       return df == 0;
+   case BRW_REGISTER_TYPE_W:
+   case BRW_REGISTER_TYPE_UW:
+      assert((d & 0xffff) == ((d >> 16) & 0xffff));
+      return (d & 0xffff) == 0;
    case BRW_REGISTER_TYPE_D:
    case BRW_REGISTER_TYPE_UD:
       return d == 0;
@@ -741,11 +750,20 @@ backend_reg::is_one() const
    if (file != IMM)
       return false;
 
+   assert(type_sz(type) > 1);
+
    switch (type) {
+   case BRW_REGISTER_TYPE_HF:
+      assert((d & 0xffff) == ((d >> 16) & 0xffff));
+      return (d & 0xffff) == 0x3c00;
    case BRW_REGISTER_TYPE_F:
       return f == 1.0f;
    case BRW_REGISTER_TYPE_DF:
       return df == 1.0;
+   case BRW_REGISTER_TYPE_W:
+   case BRW_REGISTER_TYPE_UW:
+      assert((d & 0xffff) == ((d >> 16) & 0xffff));
+      return (d & 0xffff) == 1;
    case BRW_REGISTER_TYPE_D:
    case BRW_REGISTER_TYPE_UD:
       return d == 1;
@@ -763,11 +781,19 @@ backend_reg::is_negative_one() const
    if (file != IMM)
       return false;
 
+   assert(type_sz(type) > 1);
+
    switch (type) {
+   case BRW_REGISTER_TYPE_HF:
+      assert((d & 0xffff) == ((d >> 16) & 0xffff));
+      return (d & 0xffff) == 0xbc00;
    case BRW_REGISTER_TYPE_F:
       return f == -1.0;
    case BRW_REGISTER_TYPE_DF:
       return df == -1.0;
+   case BRW_REGISTER_TYPE_W:
+      assert((d & 0xffff) == ((d >> 16) & 0xffff));
+      return (d & 0xffff) == 0xffff;
    case BRW_REGISTER_TYPE_D:
       return d == -1;
    case BRW_REGISTER_TYPE_Q:
-- 
2.17.1