From 397cc6b217babb7ed50b4567d28cf387bcb51cf8 Mon Sep 17 00:00:00 2001
From: cracyc <cracyc@users.noreply.github.com>
Date: Sat, 11 Feb 2023 19:26:01 -0600
Subject: i386: add fxsave and fxstor

---
 src/devices/cpu/i386/pentops.hxx | 66 +++++++++++++++++++++++++++++++++++++++-
 1 file changed, 65 insertions(+), 1 deletion(-)

diff --git a/src/devices/cpu/i386/pentops.hxx b/src/devices/cpu/i386/pentops.hxx
index a43ecf30161..4d5b4a88a7e 100644
--- a/src/devices/cpu/i386/pentops.hxx
+++ b/src/devices/cpu/i386/pentops.hxx
@@ -2801,12 +2801,76 @@ void i386_device::sse_group_0fae()  // Opcode 0f ae
 		uint32_t ea;
 		switch ( (modm & 0x38) >> 3 )
 		{
+			case 0: // fxsave
+			{
+				u8 atag = 0;
+				ea = GetEA(modm, 1);
+				WRITE16(ea + 0, m_x87_cw);
+				WRITE16(ea + 2, m_x87_sw);
+				for(int i = 0; i < 8; i++)
+					if((m_x87_tw & (3 << i)) != 3) atag |= 1 << i;
+				WRITE16(ea + 4, atag);
+				WRITE16(ea + 6, m_x87_opcode);
+				WRITE32(ea + 8, m_x87_inst_ptr);
+				WRITE32(ea + 12, m_x87_cs);
+				WRITE32(ea + 16, m_x87_data_ptr);
+				WRITE32(ea + 20, m_x87_ds);
+				WRITE32(ea + 24, m_mxcsr);
+				WRITE32(ea + 28, 0); // mxcsr_mask
+				for(int i = 0; i < 8; i++)
+				{
+					WRITE64(ea + i*16 + 32, m_x87_reg[i].low);
+					WRITE64(ea + i*16 + 40, m_x87_reg[i].high);
+				}
+				for(int i = 0; i < 8; i++)
+				{
+					WRITE64(ea + i*16 + 160, m_sse_reg[i].q[0]);
+					WRITE64(ea + i*16 + 168, m_sse_reg[i].q[1]);
+				}
+				break;
+			}
+			case 1:
+			{
+				u8 atag;
+				ea = GetEA(modm, 0);
+				x87_write_cw(READ16(ea));
+				m_x87_sw = READ16(ea + 2);
+				atag = READ8(ea + 4);
+				m_x87_opcode = READ16(ea + 6);
+				m_x87_inst_ptr = READ32(ea + 8);
+				m_x87_cs = READ16(ea + 12);
+				m_x87_data_ptr = READ32(ea + 16);
+				m_x87_ds = READ16(ea + 20);
+				m_mxcsr = READ32(ea + 24);
+				// mxcsr_mask
+				for(int i = 0; i < 8; i++)
+				{
+					int tag;
+					m_x87_reg[i].low = READ64(ea + i*16 + 32);
+					m_x87_reg[i].high = READ16(ea + i*16 + 40);
+					if(!(atag & (1 << i)))
+						tag = X87_TW_EMPTY;
+					if(floatx80_is_zero(m_x87_reg[i]))
+						tag = X87_TW_ZERO;
+					else if(floatx80_is_inf(m_x87_reg[i]) || floatx80_is_nan(m_x87_reg[i]))
+						tag = X87_TW_SPECIAL;
+					else
+						tag = X87_TW_VALID;
+					x87_set_tag(i, tag);
+				}
+				for(int i = 0; i < 8; i++)
+				{
+					m_sse_reg[i].q[0] = READ64(ea + i*16 + 160);
+					m_sse_reg[i].q[1] = READ64(ea + i*16 + 168);
+				}
+				break;
+			}
 			case 2: // ldmxcsr m32
 				ea = GetEA(modm, 0);
 				m_mxcsr = READ32(ea);
 				break;
 			case 3: // stmxcsr m32
-				ea = GetEA(modm, 0);
+				ea = GetEA(modm, 1);
 				WRITE32(ea, m_mxcsr);
 				break;
 			case 7: // clflush m8
-- 
cgit v1.2.3