From 8ab7d8175c62d6f5242a64d1b0fdbc5f534638e4 Mon Sep 17 00:00:00 2001
From: MerryMage <MerryMage@users.noreply.github.com>
Date: Tue, 6 Feb 2018 23:04:23 +0000
Subject: [PATCH] impl: Add AdvSIMDExpandImm

---
 src/frontend/A64/translate/impl/impl.cpp | 54 ++++++++++++++++++++++++
 src/frontend/A64/translate/impl/impl.h   |  1 +
 2 files changed, 55 insertions(+)

diff --git a/src/frontend/A64/translate/impl/impl.cpp b/src/frontend/A64/translate/impl/impl.cpp
index 68a9e859..973ed45b 100644
--- a/src/frontend/A64/translate/impl/impl.cpp
+++ b/src/frontend/A64/translate/impl/impl.cpp
@@ -56,6 +56,60 @@ boost::optional<TranslatorVisitor::BitMasks> TranslatorVisitor::DecodeBitMasks(b
     return BitMasks{wmask, tmask};
 }
 
+u64 TranslatorVisitor::AdvSIMDExpandImm(bool op, Imm<4> cmode, Imm<8> imm8) {
+    switch (cmode.Bits<1, 3>()) {
+    case 0b000:
+        return Common::Replicate<u64>(imm8.ZeroExtend<u64>(), 32);
+    case 0b001:
+        return Common::Replicate<u64>(imm8.ZeroExtend<u64>() << 8, 32);
+    case 0b010:
+        return Common::Replicate<u64>(imm8.ZeroExtend<u64>() << 16, 32);
+    case 0b011:
+        return Common::Replicate<u64>(imm8.ZeroExtend<u64>() << 24, 32);
+    case 0b100:
+        return Common::Replicate<u64>(imm8.ZeroExtend<u64>(), 16);
+    case 0b101:
+        return Common::Replicate<u64>(imm8.ZeroExtend<u64>() << 8, 16);
+    case 0b110:
+        if (!cmode.Bit<0>()) {
+            return Common::Replicate<u64>((imm8.ZeroExtend<u64>() << 8) | Common::Ones<u64>(8), 32);
+        }
+        return Common::Replicate<u64>((imm8.ZeroExtend<u64>() << 16) | Common::Ones<u64>(16), 32);
+    case 0b111:
+        if (!cmode.Bit<0>() && !op) {
+            return Common::Replicate<u64>(imm8.ZeroExtend<u64>(), 8);
+        }
+        if (!cmode.Bit<0>() && op) {
+            u64 result = 0;
+            result |= imm8.Bit<0>() ? Common::Ones<u64>(8) << (0 * 8) : 0;
+            result |= imm8.Bit<1>() ? Common::Ones<u64>(8) << (1 * 8) : 0;
+            result |= imm8.Bit<2>() ? Common::Ones<u64>(8) << (2 * 8) : 0;
+            result |= imm8.Bit<3>() ? Common::Ones<u64>(8) << (3 * 8) : 0;
+            result |= imm8.Bit<4>() ? Common::Ones<u64>(8) << (4 * 8) : 0;
+            result |= imm8.Bit<5>() ? Common::Ones<u64>(8) << (5 * 8) : 0;
+            result |= imm8.Bit<6>() ? Common::Ones<u64>(8) << (6 * 8) : 0;
+            result |= imm8.Bit<7>() ? Common::Ones<u64>(8) << (7 * 8) : 0;
+            return result;
+        }
+        if (cmode.Bit<0>() && !op) {
+            u64 result = 0;
+            result |= imm8.Bit<7>() ? 0x80000000 : 0;
+            result |= imm8.Bit<6>() ? 0x3E000000 : 0x40000000;
+            result |= imm8.Bits<0, 5, u64>() << 19;
+            return Common::Replicate<u64>(result, 32);
+        }
+        if (cmode.Bit<0>() && op) {
+            u64 result = 0;
+            result |= imm8.Bit<7>() ? 0x80000000'00000000 : 0;
+            result |= imm8.Bit<6>() ? 0x3FC00000'00000000 : 0x40000000'00000000;
+            result |= imm8.Bits<0, 5, u64>() << 48;
+            return result;
+        }
+    }
+    UNREACHABLE();
+    return 0;
+}
+
 IR::U32U64 TranslatorVisitor::I(size_t bitsize, u64 value) {
     switch (bitsize) {
     case 32:
diff --git a/src/frontend/A64/translate/impl/impl.h b/src/frontend/A64/translate/impl/impl.h
index 1f1e8371..a3159e44 100644
--- a/src/frontend/A64/translate/impl/impl.h
+++ b/src/frontend/A64/translate/impl/impl.h
@@ -40,6 +40,7 @@ struct TranslatorVisitor final {
     };
 
     boost::optional<BitMasks> DecodeBitMasks(bool N, Imm<6> immr, Imm<6> imms, bool immediate);
+    u64 AdvSIMDExpandImm(bool op, Imm<4> cmode, Imm<8> imm8);
 
     IR::U32U64 I(size_t bitsize, u64 value);
     IR::UAny X(size_t bitsize, Reg reg);