Constant numeric local variables can be used in places were literals are
expected if they're initialized with a static expression.
Storing such constant in ctx->static_initializers allows copy-prop to
handle such cases properly.
This fixes the assertion error
"sm4_generate_vsir_instr_expr Failed assertion: dst_type->e.numeric.type == HLSL_TYPE_BOOL"
which occurs when compiling the following HLSL shader using the ps_4_0 target profile:
uniform float4 x;
uniform bool b;
float4 main() : SV_Target
{
if (!b)
clip(x.x);
else
clip(x.y);
return x;
}
When no descriptor mapping is specified, the backend will just
build the usual default mapping. Otherwise the explicit mapping
is used.
Once all backends support the explicit mapping, we'll be able to
handle generating the default mapping in the shader runner core
rather than having each backend implement its own algorithm.
So far only the d3d12 backend supports explicit descriptor
mapping.
MSL doesn't seem to have any special handling for undefined values,
differently from SPIR-V. Thus we just emit zeros.
UNDEF registers are sometimes created by the DXIL parser,
for example in sm6_parser_emit_composite_construct().
For an if block
if (cond)
{
<then_block>
}
else
{
<else_block>
}
We flatten it by first replacing any store instruction `v[[k]] = x`
in the then_block with the following:
1: load(v[[k]])
2: cond ? x : @1
3: v[[k]] = @2
Similarly, we replace any store instruction `v[[k]] = x` in the
else_block with the following:
1: load(v[[k]])
2: cond ? @1 : x
3: v[[k]] = @2
Then we can concatenate <then_block> and <else_block> together and
get rid of the if block.
