Use the correct type for the constant for matrix/scalar division
When a matrix is divided by a scalar it tries to take the reciprocal
of the scalar to convert the operation into a multiply. However it was
always doing this by making a 32-bit constant. If the scalar is a
double then this would end up making an FDiv instruction with
different types in the operands.
This patch adds a helper method called makeFpConstant which makes a
floating-point constant of the given type. The code to take the
reciprocal now uses it to make the same type as the result.
Fixes https://github.com/KhronosGroup/glslang/issues/1278
diff --git a/SPIRV/GlslangToSpv.cpp b/SPIRV/GlslangToSpv.cpp
index 1527fec..11257f0 100644
--- a/SPIRV/GlslangToSpv.cpp
+++ b/SPIRV/GlslangToSpv.cpp
@@ -4137,7 +4137,8 @@
case spv::OpFDiv:
if (builder.isMatrix(left) && builder.isScalar(right)) {
// turn matrix / scalar into a multiply...
- right = builder.createBinOp(spv::OpFDiv, builder.getTypeId(right), builder.makeFloatConstant(1.0F), right);
+ spv::Id resultType = builder.getTypeId(right);
+ right = builder.createBinOp(spv::OpFDiv, resultType, builder.makeFpConstant(resultType, 1.0), right);
op = spv::OpMatrixTimesScalar;
} else
firstClass = false;
diff --git a/SPIRV/SpvBuilder.cpp b/SPIRV/SpvBuilder.cpp
index 10d0d50..b509edd 100644
--- a/SPIRV/SpvBuilder.cpp
+++ b/SPIRV/SpvBuilder.cpp
@@ -848,6 +848,23 @@
return c->getResultId();
}
+Id Builder::makeFpConstant(Id type, double d, bool specConstant)
+{
+ assert(isFloatType(type));
+
+ switch (getScalarTypeWidth(type)) {
+ case 16:
+ return makeFloat16Constant(d, specConstant);
+ case 32:
+ return makeFloatConstant(d, specConstant);
+ case 64:
+ return makeDoubleConstant(d, specConstant);
+ }
+
+ assert(false);
+}
+
+
Id Builder::findCompositeConstant(Op typeClass, const std::vector<Id>& comps)
{
Instruction* constant = 0;
diff --git a/SPIRV/SpvBuilder.h b/SPIRV/SpvBuilder.h
index d4d2719..25495fb 100755
--- a/SPIRV/SpvBuilder.h
+++ b/SPIRV/SpvBuilder.h
@@ -226,6 +226,7 @@
Id makeFloatConstant(float f, bool specConstant = false);
Id makeDoubleConstant(double d, bool specConstant = false);
Id makeFloat16Constant(float f16, bool specConstant = false);
+ Id makeFpConstant(Id type, double d, bool specConstant = false);
// Turn the array of constants into a proper spv constant of the requested type.
Id makeCompositeConstant(Id type, const std::vector<Id>& comps, bool specConst = false);