From 490bebbd9a48345abf8d157acb378d07811be654 Mon Sep 17 00:00:00 2001
From: Lioncash <mathew1800@gmail.com>
Date: Fri, 8 Mar 2019 06:20:50 -0500
Subject: [PATCH 1/2] common/fp/unpacked: Add FPUnpackCV

Adds a template function that performs the same behavior as in the ARM
pseudocode, and utilizes it in FPConvert, which will be necessary for
half-float support.
---
 src/common/fp/op/FPConvert.cpp | 2 +-
 src/common/fp/unpacked.h       | 6 ++++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/common/fp/op/FPConvert.cpp b/src/common/fp/op/FPConvert.cpp
index 559d0242..49524906 100644
--- a/src/common/fp/op/FPConvert.cpp
+++ b/src/common/fp/op/FPConvert.cpp
@@ -59,7 +59,7 @@ FPT_TO FPConvertNaN(FPT_FROM op) {
 
 template <typename FPT_TO, typename FPT_FROM>
 FPT_TO FPConvert(FPT_FROM op, FPCR fpcr, RoundingMode rounding_mode, FPSR& fpsr) {
-    const auto [type, sign, value] = FPUnpack<FPT_FROM>(op, fpcr, fpsr);
+    const auto [type, sign, value] = FPUnpackCV<FPT_FROM>(op, fpcr, fpsr);
     const bool is_althp = Common::BitSize<FPT_TO>() == 16 && fpcr.AHP();
 
     if (type == FPType::SNaN || type == FPType::QNaN) {
diff --git a/src/common/fp/unpacked.h b/src/common/fp/unpacked.h
index 132fedd0..943ee461 100644
--- a/src/common/fp/unpacked.h
+++ b/src/common/fp/unpacked.h
@@ -54,6 +54,12 @@ constexpr FPUnpacked ToNormalized(bool sign, int exponent, u64 value) {
 template<typename FPT>
 std::tuple<FPType, bool, FPUnpacked> FPUnpack(FPT op, FPCR fpcr, FPSR& fpsr);
 
+template<typename FPT>
+std::tuple<FPType, bool, FPUnpacked> FPUnpackCV(FPT op, FPCR fpcr, FPSR& fpsr) {
+    fpcr.FZ16(false);
+    return FPUnpack(op, fpcr, fpsr);
+}
+
 template<typename FPT>
 FPT FPRoundBase(FPUnpacked op, FPCR fpcr, RoundingMode rounding, FPSR& fpsr);
 

From 99c494bae943aaa41c65d00fdf8edbf498159575 Mon Sep 17 00:00:00 2001
From: Lioncash <mathew1800@gmail.com>
Date: Fri, 8 Mar 2019 06:24:03 -0500
Subject: [PATCH 2/2] common/fp/unpacked: Add FPRoundCV

Corresponds to the equivalent pseudocode within the ARMv8 reference
manual. This will be necessary for supporting half-precision
floating-point.

This also makes use of it within FPConvert
---
 src/common/fp/op/FPConvert.cpp | 2 +-
 src/common/fp/unpacked.h       | 6 ++++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/common/fp/op/FPConvert.cpp b/src/common/fp/op/FPConvert.cpp
index 49524906..87f965a7 100644
--- a/src/common/fp/op/FPConvert.cpp
+++ b/src/common/fp/op/FPConvert.cpp
@@ -93,7 +93,7 @@ FPT_TO FPConvert(FPT_FROM op, FPCR fpcr, RoundingMode rounding_mode, FPSR& fpsr)
         return FPInfo<FPT_TO>::Zero(sign);
     }
 
-    return FPRoundBase<FPT_TO>(value, fpcr, rounding_mode, fpsr);
+    return FPRoundCV<FPT_TO>(value, fpcr, rounding_mode, fpsr);
 }
 
 template u64 FPConvert<u64, u32>(u32 op, FPCR fpcr, RoundingMode rounding_mode, FPSR& fpsr);
diff --git a/src/common/fp/unpacked.h b/src/common/fp/unpacked.h
index 943ee461..ae206c19 100644
--- a/src/common/fp/unpacked.h
+++ b/src/common/fp/unpacked.h
@@ -69,6 +69,12 @@ FPT FPRound(FPUnpacked op, FPCR fpcr, RoundingMode rounding, FPSR& fpsr) {
     return FPRoundBase<FPT>(op, fpcr, rounding, fpsr);
 }
 
+template<typename FPT>
+FPT FPRoundCV(FPUnpacked op, FPCR fpcr, RoundingMode rounding, FPSR& fpsr) {
+    fpcr.FZ16(false);
+    return FPRoundBase<FPT>(op, fpcr, rounding, fpsr);
+}
+
 template<typename FPT>
 FPT FPRound(FPUnpacked op, FPCR fpcr, FPSR& fpsr) {
     return FPRound<FPT>(op, fpcr, fpcr.RMode(), fpsr);