[Mesa-dev] [PATCH 3/3] intel/compiler: Relax mixed type restriction for saturating immediates

[Ian Romanick]

From: Ian Romanick <ian.d.romanick at intel.com>

At the time of commit 7bc6e455e23 (i965: Add support for saturating
immediates.) we thought mixed type saturates would be impossible.  We
were only thinking about type converting moves from D to F, for
example.  However, type converting moves w/saturate from F to DF are
definitely possible.  This change minimally relaxes the restriction to
allow cases that I have been able trigger via piglit tests.

Fixes new piglit tests:
 - arb_gpu_shader_fp64/execution/built-in-functions/fs-sign-sat-neg-abs.shader_test
 - arb_gpu_shader_fp64/execution/built-in-functions/vs-sign-sat-neg-abs.shader_test

Signed-off-by: Ian Romanick <ian.d.romanick at intel.com>
Cc: mesa-stable at lists.freedesktop.org
---
 src/intel/compiler/brw_fs.cpp   | 13 +++++++++++--
 src/intel/compiler/brw_vec4.cpp | 13 +++++++++++--
 2 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/src/intel/compiler/brw_fs.cpp b/src/intel/compiler/brw_fs.cpp
index f683b4fd4d0..064a2eb9bd8 100644
--- a/src/intel/compiler/brw_fs.cpp
+++ b/src/intel/compiler/brw_fs.cpp
@@ -2373,10 +2373,19 @@ fs_visitor::opt_algebraic()
             break;
 
          if (inst->saturate) {
-            if (inst->dst.type != inst->src[0].type)
+            /* Full mixed-type saturates don't happen.  However, we can end up
+             * with things like:
+             *
+             *    mov.sat(8) g21<1>DF       -1F
+             *
+             * Other mixed-size-but-same-base-type cases may also be possible.
+             */
+            if (inst->dst.type != inst->src[0].type &&
+                inst->dst.type != BRW_REGISTER_TYPE_DF &&
+                inst->src[0].type != BRW_REGISTER_TYPE_F)
                assert(!"unimplemented: saturate mixed types");
 
-            if (brw_saturate_immediate(inst->dst.type,
+            if (brw_saturate_immediate(inst->src[0].type,
                                        &inst->src[0].as_brw_reg())) {
                inst->saturate = false;
                progress = true;
diff --git a/src/intel/compiler/brw_vec4.cpp b/src/intel/compiler/brw_vec4.cpp
index 092007dc6ea..0e40ddd0b3d 100644
--- a/src/intel/compiler/brw_vec4.cpp
+++ b/src/intel/compiler/brw_vec4.cpp
@@ -799,10 +799,19 @@ vec4_visitor::opt_algebraic()
             break;
 
          if (inst->saturate) {
-            if (inst->dst.type != inst->src[0].type)
+            /* Full mixed-type saturates don't happen.  However, we can end up
+             * with things like:
+             *
+             *    mov.sat(8) g21<1>DF       -1F
+             *
+             * Other mixed-size-but-same-base-type cases may also be possible.
+             */
+            if (inst->dst.type != inst->src[0].type &&
+                inst->dst.type != BRW_REGISTER_TYPE_DF &&
+                inst->src[0].type != BRW_REGISTER_TYPE_F)
                assert(!"unimplemented: saturate mixed types");
 
-            if (brw_saturate_immediate(inst->dst.type,
+            if (brw_saturate_immediate(inst->src[0].type,
                                        &inst->src[0].as_brw_reg())) {
                inst->saturate = false;
                progress = true;
-- 
2.14.4