SpirvShader: Implement GLSLstd450Ldexp
Bug: b/126873455
Tests: dEQP-VK.glsl.builtin.function.common.ldexp.*
Change-Id: Ie8ab0db7a7f712c5f876f521773217be5f350e4f
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/28648
Tested-by: Ben Clayton <bclayton@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
diff --git a/src/Pipeline/SpirvShader.cpp b/src/Pipeline/SpirvShader.cpp
index fb7e620..aff801e 100644
--- a/src/Pipeline/SpirvShader.cpp
+++ b/src/Pipeline/SpirvShader.cpp
@@ -59,6 +59,14 @@
{
return a * b + c;
}
+
+ // Returns the exponent of the floating point number f.
+ // Assumes IEEE 754
+ rr::RValue<sw::SIMD::Int> Exponent(rr::RValue<sw::SIMD::Float> f)
+ {
+ auto v = rr::As<sw::SIMD::UInt>(f);
+ return (sw::SIMD::Int((v >> sw::SIMD::UInt(23)) & sw::SIMD::UInt(0xFF)) - sw::SIMD::Int(126));
+ }
}
namespace sw
@@ -3241,6 +3249,21 @@
}
break;
}
+ case GLSLstd450Ldexp:
+ {
+ auto significand = GenericValue(this, routine, insn.word(5));
+ auto exponent = GenericValue(this, routine, insn.word(6));
+ for (auto i = 0u; i < type.sizeInComponents; i++)
+ {
+ // Assumes IEEE 754
+ auto significandExponent = Exponent(significand.Float(i));
+ auto combinedExponent = exponent.Int(i) + significandExponent;
+ SIMD::UInt v = (significand.UInt(i) & SIMD::UInt(0x807FFFFF)) |
+ (SIMD::UInt(combinedExponent + SIMD::Int(126)) << SIMD::UInt(23));
+ dst.move(i, As<SIMD::Float>(v));
+ }
+ break;
+ }
default:
UNIMPLEMENTED("Unhandled ExtInst %d", extInstIndex);
}
@@ -3319,7 +3342,7 @@
auto isNotZero = CmpNEQ(v & SIMD::UInt(0x7FFFFFFF), SIMD::UInt(0));
auto zeroSign = v & SIMD::UInt(0x80000000) & ~isNotZero;
auto significand = As<SIMD::Float>((v & SIMD::UInt(0x807FFFFF) | SIMD::UInt(0x3F000000)) & isNotZero | zeroSign);
- auto exponent = (SIMD::Int((v >> SIMD::UInt(23)) & SIMD::UInt(0xFF)) - SIMD::Int(126)) & SIMD::Int(isNotZero);
+ auto exponent = Exponent(val) & SIMD::Int(isNotZero);
return std::make_pair(significand, exponent);
}