SpirvShader: Implement GLSLstd450InverseSqrt
RcpSqrt_pp is not accurate enough to be used on non-relaxed precision types.
Bug: b/126873455
Tests: dEQP-VK.glsl.builtin.precision.inversesqrt.*
Change-Id: I3e34d28dbd863c9cb14cf6c79afe08a1992b5478
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/28697
Tested-by: Ben Clayton <bclayton@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
diff --git a/src/Pipeline/SpirvShader.cpp b/src/Pipeline/SpirvShader.cpp
index d1d416d..797ef73 100644
--- a/src/Pipeline/SpirvShader.cpp
+++ b/src/Pipeline/SpirvShader.cpp
@@ -3463,7 +3463,23 @@
}
case GLSLstd450InverseSqrt:
{
- UNIMPLEMENTED("GLSLstd450InverseSqrt");
+ auto val = GenericValue(this, routine, insn.word(5));
+ Decorations d;
+ ApplyDecorationsForId(&d, insn.word(5));
+ if (d.RelaxedPrecision)
+ {
+ for (auto i = 0u; i < type.sizeInComponents; i++)
+ {
+ dst.move(i, RcpSqrt_pp(val.Float(i)));
+ }
+ }
+ else
+ {
+ for (auto i = 0u; i < type.sizeInComponents; i++)
+ {
+ dst.move(i, SIMD::Float(1.0f) / Sqrt(val.Float(i)));
+ }
+ }
break;
}
case GLSLstd450Determinant: