commit 1c75921db9c0095d7ab96c686f51efa2951b2f4f
author Jiawei Shao <jiawei.shao@intel.com> Sun May 15 13:53:21 2022 +0000
committer Dawn LUCI CQ <dawn-scoped@luci-project-accounts.iam.gserviceaccount.com> Sun May 15 13:53:21 2022 +0000
tree d96cd58a262196b224960d0951c84f9ea97ff985
parent 5a951cd6c7ba654ed46d825f46b832106d6f3977

tint: fix translation of DP4a on HLSL

This patch adds a workaround on a DXC error in the translation of DP4a
functions that the third parameter "acc" of both dot4add_i8packed() and
dot4add_u8packed() can only be a variable, or a compile error will be
generated.

Bug: tint:1497
Test: tint_unittests
Change-Id: I263d27fb18bd354e0c9110f60cbc98860cf7afe5
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/90027
Reviewed-by: Ben Clayton <bclayton@google.com>
Commit-Queue: Jiawei Shao <jiawei.shao@intel.com>
Kokoro: Kokoro <noreply+kokoro@google.com>

src/tint/writer/hlsl/generator_impl.cc

diff --git a/src/tint/writer/hlsl/generator_impl.cc b/src/tint/writer/hlsl/generator_impl.cc
index fb4efb6..b7020f6 100644
--- a/src/tint/writer/hlsl/generator_impl.cc
+++ b/src/tint/writer/hlsl/generator_impl.cc
@@ -2045,9 +2045,11 @@
             std::string functionName;
             switch (builtin->Type()) {
                 case sem::BuiltinType::kDot4I8Packed:
+                    line(b) << "int accumulator = 0;";
                     functionName = "dot4add_i8packed";
                     break;
                 case sem::BuiltinType::kDot4U8Packed:
+                    line(b) << "uint accumulator = 0u;";
                     functionName = "dot4add_u8packed";
                     break;
                 default:
@@ -2056,7 +2058,7 @@
                     return false;
             }
             line(b) << "return " << functionName << "(" << params[0] << ", " << params[1]
-                    << ", 0);";
+                    << ", accumulator);";
 
             return true;
         });

src/tint/writer/hlsl/generator_impl_builtin_test.cc

diff --git a/src/tint/writer/hlsl/generator_impl_builtin_test.cc b/src/tint/writer/hlsl/generator_impl_builtin_test.cc
index 64ef740..6c573ff 100644
--- a/src/tint/writer/hlsl/generator_impl_builtin_test.cc
+++ b/src/tint/writer/hlsl/generator_impl_builtin_test.cc
@@ -741,7 +741,8 @@
 
     ASSERT_TRUE(gen.Generate()) << gen.error();
     EXPECT_EQ(gen.result(), R"(int tint_dot4I8Packed(uint param_0, uint param_1) {
-  return dot4add_i8packed(param_0, param_1, 0);
+  int accumulator = 0;
+  return dot4add_i8packed(param_0, param_1, accumulator);
 }
 
 [numthreads(1, 1, 1)]
@@ -769,7 +770,8 @@
 
     ASSERT_TRUE(gen.Generate()) << gen.error();
     EXPECT_EQ(gen.result(), R"(uint tint_dot4U8Packed(uint param_0, uint param_1) {
-  return dot4add_u8packed(param_0, param_1, 0);
+  uint accumulator = 0u;
+  return dot4add_u8packed(param_0, param_1, accumulator);
 }
 
 [numthreads(1, 1, 1)]