diff --git a/Makefile.am b/Makefile.am
index cfb225f9..9e761ef3 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -170,6 +170,7 @@ vkd3d_shader_tests = \
 	tests/hlsl/side-effects.shader_test \
 	tests/hlsl/sign.shader_test \
 	tests/hlsl/single-numeric-initializer.shader_test \
+	tests/hlsl/sm1-const-folding.shader_test \
 	tests/hlsl/sm6-ternary.shader_test \
 	tests/hlsl/sm6-uav-rwtexture.shader_test \
 	tests/hlsl/smoothstep.shader_test \
diff --git a/tests/hlsl/sm1-const-folding.shader_test b/tests/hlsl/sm1-const-folding.shader_test
new file mode 100644
index 00000000..1766de38
--- /dev/null
+++ b/tests/hlsl/sm1-const-folding.shader_test
@@ -0,0 +1,146 @@
+% Test the interaction between integer constant folding and the fact
+% that integers are secretly considered floats in SM1-3
+
+[pixel shader]
+float4 main() : SV_TARGET
+{
+    uint x = 3000000000u;
+    return float4(x, 0.0, 0.0, 0.0);
+}
+
+[test]
+draw quad
+probe all rgba (3.0e+009, 0.0, 0.0, 0.0)
+
+% The uint value is never casted to int on SM1-3, just casted to float and treated as such
+[pixel shader]
+float4 main() : SV_TARGET
+{
+    int x = 3000000000u;
+    return float4(x, 0.0, 0.0, 0.0);
+}
+
+[test]
+draw quad
+if(sm<4) todo probe all rgba (3.0e+009, 0.0, 0.0, 0.0)
+if(sm>=4) probe all rgba (-1.29496730e+009, 0.0, 0.0, 0.0)
+
+% On SM1-5 (FXC) the literal is considered signed independently of its value and casted to uint;
+% on SM1-3 compilation fails because the uint would be negative
+[pixel shader fail(sm<4) todo(sm<4)]
+float4 main() : SV_TARGET
+{
+    uint x = 3000000000;
+    return float4(x, 0.0, 0.0, 0.0);
+}
+
+[test]
+draw quad
+if(sm>=4) probe all rgba (3.0e+009, 0.0, 0.0, 0.0)
+
+[pixel shader]
+float4 main() : SV_TARGET
+{
+    int x = 3000000000;
+    return float4(x, 0.0, 0.0, 0.0);
+}
+
+[test]
+draw quad
+probe all rgba (-1.29496730e+009, 0.0, 0.0, 0.0)
+
+[pixel shader]
+float4 main() : SV_TARGET
+{
+    return float4(3000000000u, 0.0, 0.0, 0.0);
+}
+
+[test]
+draw quad
+probe all rgba (3.0e+009, 0.0, 0.0, 0.0)
+
+% Unsuffixed literals can instead be considered unsigned on SM6
+[pixel shader]
+float4 main() : SV_TARGET
+{
+    return float4(3000000000, 0.0, 0.0, 0.0);
+}
+
+[test]
+draw quad
+if(sm<6) probe all rgba (-1.29496730e+009, 0.0, 0.0, 0.0)
+if(sm>=6) probe all rgba (3.0e+009, 0.0, 0.0, 0.0)
+
+% Constant folding is done with uint semantics before converting to float;
+% so constant folding seems to happen before converting integer operations to floats
+[pixel shader]
+float4 main() : SV_TARGET
+{
+    uint x = 3000000000u + 3000000000u;
+    return float4(x, 0.0, 0.0, 0.0);
+}
+
+[test]
+draw quad
+probe all rgba (1.70503270e+009, 0.0, 0.0, 0.0)
+
+% SM1-3 complains that uint values must be positive, but it's not clear why this is a problem here:
+% the sum should be done before casting to uint, and the result of the int sum should be positive,
+% so it seems that the declared type of x means something on how constant folding is done.
+% I'm not sure what's happening for SM4 anyway
+[pixel shader fail(sm<4) todo(sm<4)]
+float4 main() : SV_TARGET
+{
+    uint x = 3000000000 + 3000000000;
+    return float4(x, 0.0, 0.0, 0.0);
+}
+
+[test]
+draw quad
+todo probe all rgba (2.14748365e+009, 0.0, 0.0, 0.0)
+
+% Again, no idea of what's happening here
+[pixel shader]
+float4 main() : SV_TARGET
+{
+    int x = 3000000000 + 3000000000;
+    return float4(x, 0.0, 0.0, 0.0);
+}
+
+[test]
+draw quad
+todo probe all rgba (-2.14748365e+009, 0.0, 0.0, 0.0)
+
+% This makes sense
+[pixel shader]
+float4 main() : SV_TARGET
+{
+    return float4(3000000000u + 3000000000u, 0.0, 0.0, 0.0);
+}
+
+[test]
+draw quad
+probe all rgba (1.70503270e+009, 0.0, 0.0, 0.0)
+
+% This does not again
+[pixel shader]
+float4 main() : SV_TARGET
+{
+    return float4(3000000000 + 3000000000, 0.0, 0.0, 0.0);
+}
+
+[test]
+draw quad
+todo probe all rgba (-2.14748365e+009, 0.0, 0.0, 0.0)
+
+% Explicit float literals use float semantics, at least
+[pixel shader]
+float4 main() : SV_TARGET
+{
+    float x = 3000000000.0 + 3000000000.0;
+    return float4(x, 0.0, 0.0, 0.0);
+}
+
+[test]
+draw quad
+probe all rgba (6.0e+009, 0.0, 0.0, 0.0)