microsoft / microsoft/DirectXShaderCompiler

`-Wimplicit-int-float-conversion` or `-Wconversion` don't report "float -> int" conversion warnings

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bug
Dominant language
C++
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Description

Description
I expect -Wimplicit-int-float-conversion or -Wconversion to produce a warning when doing implicit "float -> int" conversion.
Example in Clang: https://godbolt.org/z/WahdMPs71

Steps to Reproduce

StructuredBuffer<uint> In;
RWStructuredBuffer<float> Out;

[numthreads(1,1,1)]
void main(uint thread : SV_DispatchThreadID)
{
    Out[thread] = In[thread];
}

Commandline: -Wconversion -WX -T cs_6_6 -E main

Godbolt: https://godbolt.org/z/6xKasdxdx

Actual Behavior
DXC produces no warnings

Environment

  • DXC version 1.8.2407
  • Host Operating System W11 23H2

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Research direction

Start by reproducing the supplied HLSL compute-shader example with DXC using -Wconversion -WX -T cs_6_6 -E main, then compare its diagnostics with the linked Clang result. Done means DXC reports the implicit float-to-int conversion warning for the shown assignment.

Written by the indexing model from the issue text.

Assessment

Tech stack
cpp
Domain
compilers
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
45/100

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