From 59db2c191a018a9d86fc905bae33008dab97ded6 Mon Sep 17 00:00:00 2001
From: MerryMage <MerryMage@users.noreply.github.com>
Date: Sun, 10 May 2020 15:09:37 +0100
Subject: [PATCH] VFPv3: Implement VMOV (immediate)

---
 src/frontend/A32/decoder/vfp.inc              |  2 +-
 .../A32/disassembler/disassembler_arm.cpp     | 18 +++++++++++
 .../A32/translate/impl/translate_arm.h        |  1 +
 src/frontend/A32/translate/impl/vfp.cpp       | 30 +++++++++++++++++++
 4 files changed, 50 insertions(+), 1 deletion(-)

diff --git a/src/frontend/A32/decoder/vfp.inc b/src/frontend/A32/decoder/vfp.inc
index aca0c62e..c82c81b5 100644
--- a/src/frontend/A32/decoder/vfp.inc
+++ b/src/frontend/A32/decoder/vfp.inc
@@ -14,7 +14,7 @@ INST(vfp_VFMA,             "VFMA",                    "cccc11101D10nnnndddd101zN
 INST(vfp_VFMS,             "VFMS",                    "cccc11101D10nnnndddd101zN1M0mmmm") // VFPv4
 
 // Other floating-point data-processing instructions
-//INST(vfp_VMOV_imm,         "VMOV (immediate)",        "cccc11101D11vvvvdddd101z0000vvvv") // VFPv3
+INST(vfp_VMOV_imm,         "VMOV (immediate)",        "cccc11101D11vvvvdddd101z0000vvvv") // VFPv3
 INST(vfp_VMOV_reg,         "VMOV (reg)",              "cccc11101D110000dddd101z01M0mmmm") // VFPv2
 INST(vfp_VABS,             "VABS",                    "cccc11101D110000dddd101z11M0mmmm") // VFPv2
 INST(vfp_VNEG,             "VNEG",                    "cccc11101D110001dddd101z01M0mmmm") // VFPv2
diff --git a/src/frontend/A32/disassembler/disassembler_arm.cpp b/src/frontend/A32/disassembler/disassembler_arm.cpp
index 196bf3e4..b30d4c16 100644
--- a/src/frontend/A32/disassembler/disassembler_arm.cpp
+++ b/src/frontend/A32/disassembler/disassembler_arm.cpp
@@ -1232,6 +1232,24 @@ public:
         return fmt::format("vfma{}.{} {}, {}, {}", CondToString(cond), sz ? "f64" : "f32", FPRegStr(sz, Vd, D), FPRegStr(sz, Vn, N), FPRegStr(sz, Vm, M));
     }
 
+    std::string vfp_VMOV_imm(Cond cond, bool D, Imm<4> imm4H, size_t Vd, bool sz, Imm<4> imm4L) {
+        const auto imm8 = concatenate(imm4H, imm4L);
+
+        if (sz) {
+            const u64 sign = static_cast<u64>(imm8.Bit<7>());
+            const u64 exp = (imm8.Bit<6>() ? 0x3FC : 0x400) | imm8.Bits<4, 5, u64>();
+            const u64 fract = imm8.Bits<0, 3, u64>() << 48;
+            const u64 immediate = (sign << 63) | (exp << 52) | fract;
+            return fmt::format("vmov{}.f64 {}, #0x{:016x}", CondToString(cond), FPRegStr(sz, Vd, D), immediate);
+        } else {
+            const u32 sign = static_cast<u32>(imm8.Bit<7>());
+            const u32 exp = (imm8.Bit<6>() ? 0x7C : 0x80) | imm8.Bits<4, 5>();
+            const u32 fract = imm8.Bits<0, 3>() << 19;
+            const u32 immediate = (sign << 31) | (exp << 23) | fract;
+            return fmt::format("vmov{}.f32 {}, #0x{:08x}", CondToString(cond), FPRegStr(sz, Vd, D), immediate);
+        }
+    }
+
     std::string vfp_VMOV_u32_f64(Cond cond, size_t Vd, Reg t, bool D){
         return fmt::format("vmov{}.32 {}, {}", CondToString(cond), FPRegStr(true, Vd, D), t);
     }
diff --git a/src/frontend/A32/translate/impl/translate_arm.h b/src/frontend/A32/translate/impl/translate_arm.h
index 95a1d27b..f20807e5 100644
--- a/src/frontend/A32/translate/impl/translate_arm.h
+++ b/src/frontend/A32/translate/impl/translate_arm.h
@@ -377,6 +377,7 @@ struct ArmTranslatorVisitor final {
     bool vfp_VFMS(Cond cond, bool D, size_t Vn, size_t Vd, bool sz, bool N, bool M, size_t Vm);
 
     // Floating-point move instructions
+    bool vfp_VMOV_imm(Cond cond, bool D, Imm<4> imm4H, size_t Vd, bool sz, Imm<4> imm4L);
     bool vfp_VMOV_u32_f64(Cond cond, size_t Vd, Reg t, bool D);
     bool vfp_VMOV_f64_u32(Cond cond, size_t Vn, Reg t, bool N);
     bool vfp_VMOV_u32_f32(Cond cond, size_t Vn, Reg t, bool N);
diff --git a/src/frontend/A32/translate/impl/vfp.cpp b/src/frontend/A32/translate/impl/vfp.cpp
index 7f6830c1..4bf6509a 100644
--- a/src/frontend/A32/translate/impl/vfp.cpp
+++ b/src/frontend/A32/translate/impl/vfp.cpp
@@ -482,6 +482,36 @@ bool ArmTranslatorVisitor::vfp_VMOV_f64_2u32(Cond cond, Reg t2, Reg t, bool M, s
     return true;
 }
 
+// VMOV<c>.F64 <Dd>, #<imm>
+// VMOV<c>.F32 <Sd>, #<imm>
+bool ArmTranslatorVisitor::vfp_VMOV_imm(Cond cond, bool D, Imm<4> imm4H, size_t Vd, bool sz, Imm<4> imm4L) {
+    if (!ConditionPassed(cond)) {
+        return true;
+    }
+
+    if (ir.current_location.FPSCR().Stride() != 1 || ir.current_location.FPSCR().Len() != 1) {
+        return UndefinedInstruction();
+    }
+
+    const auto d = ToExtReg(sz, Vd, D);
+    const auto imm8 = concatenate(imm4H, imm4L);
+
+    if (sz) {
+        const u64 sign = static_cast<u64>(imm8.Bit<7>());
+        const u64 exp = (imm8.Bit<6>() ? 0x3FC : 0x400) | imm8.Bits<4, 5, u64>();
+        const u64 fract = imm8.Bits<0, 3, u64>() << 48;
+        const u64 immediate = (sign << 63) | (exp << 52) | fract;
+        ir.SetExtendedRegister(d, ir.Imm64(immediate));
+    } else {
+        const u32 sign = static_cast<u32>(imm8.Bit<7>());
+        const u32 exp = (imm8.Bit<6>() ? 0x7C : 0x80) | imm8.Bits<4, 5>();
+        const u32 fract = imm8.Bits<0, 3>() << 19;
+        const u32 immediate = (sign << 31) | (exp << 23) | fract;
+        ir.SetExtendedRegister(d, ir.Imm32(immediate));
+    }
+    return true;
+}
+
 // VMOV<c>.F64 <Dd>, <Dm>
 // VMOV<c>.F32 <Sd>, <Sm>
 bool ArmTranslatorVisitor::vfp_VMOV_reg(Cond cond, bool D, size_t Vd, bool sz, bool M, size_t Vm) {