shader: evaluate saturating float-to-signed conversions in runtime descriptor values

src/graphics/shader/recompiler/ir/passes/SrtWalker.cpp

@@ -82,6 +82,7 @@ bool IsRuntimeUniformOp(ValueOpcode op) {
 		case ValueOpcode::BitCastU32F32:
 		case ValueOpcode::BitCastF32U32:
 		case ValueOpcode::ConvertU32F32:
+		case ValueOpcode::ConvertS32F32:
 		case ValueOpcode::ConvertF32U32:
 		case ValueOpcode::CompositeConstructU64:
 		case ValueOpcode::CompositeExtractU64:
@@ -1038,6 +1039,23 @@ void WalkerCompiler::EmitStrict(const Node& node) {
 			c.L(done);
 			break;
 		}
+		case ValueOpcode::ConvertS32F32: {
+			// The conversion saturates and maps NaN to zero. cvttss2si's out-of-range result,
+			// INT32_MIN, is already right for negative overflow.
+			Xbyak::Label done;
+			c.movd(c.xmm0, c.eax);
+			c.xor_(c.eax, c.eax);
+			c.ucomiss(c.xmm0, c.xmm0);
+			c.jp(done, Near);
+			c.mov(c.ecx, 0x4f000000u);
+			c.movd(c.xmm1, c.ecx);
+			c.mov(c.eax, INT32_MAX);
+			c.ucomiss(c.xmm0, c.xmm1);
+			c.jae(done, Near);
+			c.cvttss2si(c.eax, c.xmm0);
+			c.L(done);
+			break;
+		}
 		case ValueOpcode::FPMul32:
 			c.movd(c.xmm0, c.eax);
 			c.movd(c.xmm1, c.ecx);