[spirv-writer] Removing GenerateConstantFloatZeroIfNeeded

Bug: tint:143
Change-Id: I81b4ec280264ec175736bae32bf1826d565ed5c0
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/28162
Reviewed-by: David Neto <dneto@google.com>
Commit-Queue: David Neto <dneto@google.com>

src/writer/spirv/builder.cc

diff --git a/src/writer/spirv/builder.cc b/src/writer/spirv/builder.cc
index 065bca1..a36b22e 100644
--- a/src/writer/spirv/builder.cc
+++ b/src/writer/spirv/builder.cc
@@ -1566,8 +1566,9 @@
     spirv_params.push_back(std::move(wgsl_params[5]));
 
     spirv_params.push_back(Operand::Int(SpvImageOperandsLodMask));
-    spirv_params.push_back(Operand::Int(
-        GenerateConstantFloatZeroIfNeeded(std::move(wgsl_params[0]))));
+    ast::type::F32Type f32;
+    ast::FloatLiteral float_0(&f32, 0.0);
+    spirv_params.push_back(Operand::Int(GenerateLiteralIfNeeded(&float_0)));
   }
   if (op == spv::Op::OpNop) {
     error_ = "unable to determine operator for: " + name;
@@ -1606,16 +1607,6 @@
   return sampled_image.to_i();
 }
 
-uint32_t Builder::GenerateConstantFloatZeroIfNeeded(Operand float_operand) {
-  if (constant_float_zero_id_ == 0) {
-    auto float_0 = result_op();
-    push_type(spv::Op::OpConstant,
-              {std::move(float_operand), float_0, Operand::Int(0)});
-    constant_float_zero_id_ = float_0.to_i();
-  }
-  return constant_float_zero_id_;
-}
-
 uint32_t Builder::GenerateAsExpression(ast::AsExpression* as) {
   auto result = result_op();
   auto result_id = result.to_i();

src/writer/spirv/builder.h

diff --git a/src/writer/spirv/builder.h b/src/writer/spirv/builder.h
index 1f828f8..4630f53 100644
--- a/src/writer/spirv/builder.h
+++ b/src/writer/spirv/builder.h
@@ -302,10 +302,6 @@
   uint32_t GenerateSampledImage(ast::type::Type* texture_type,
                                 Operand texture_operand,
                                 Operand sampler_operand);
-  /// Generates a constant float zero.
-  /// @param float_operand the f32 type operand
-  /// @returns the expression ID
-  uint32_t GenerateConstantFloatZeroIfNeeded(Operand float_operand);
   /// Generates a cast expression
   /// @param expr the expression to generate
   /// @returns the expression ID on success or 0 otherwise
@@ -450,7 +446,6 @@
   std::unordered_map<uint32_t, ast::Variable*> spirv_id_to_variable_;
   std::vector<uint32_t> merge_stack_;
   std::vector<uint32_t> continue_stack_;
-  uint32_t constant_float_zero_id_ = 0;
 };
 
 }  // namespace spirv