From 56a4d5cf83a046febd60c2932bdfcffc191f032f Mon Sep 17 00:00:00 2001
From: SarahW <pcem@pcem-emulator.co.uk>
Date: Thu, 10 Jan 2019 21:33:29 +0000
Subject: [PATCH] Use correct rounding mode on x86 and x86-64 recompiled
 versions of PF2ID. Fixes rendering errors on Unreal 3DNow! software renderer

---
 src/codegen_backend_x86-64.c      | 1 +
 src/codegen_backend_x86-64_ops.c  | 5 +++++
 src/codegen_backend_x86-64_uops.c | 2 ++
 src/codegen_backend_x86.c         | 1 +
 src/codegen_backend_x86_uops.c    | 2 ++
 src/ibm.h                         | 3 +++
 6 files changed, 14 insertions(+)

diff --git a/src/codegen_backend_x86-64.c b/src/codegen_backend_x86-64.c
index 5de8f75..29ca83a 100644
--- a/src/codegen_backend_x86-64.c
+++ b/src/codegen_backend_x86-64.c
@@ -310,6 +310,7 @@ void codegen_backend_init()
                 "stmxcsr %0\n"
                 : "=m" (cpu_state.old_fp_control)
         );
+        cpu_state.trunc_fp_control = cpu_state.old_fp_control | 0x6000;
 }
 
 void codegen_set_rounding_mode(int mode)
diff --git a/src/codegen_backend_x86-64_ops.c b/src/codegen_backend_x86-64_ops.c
index f077960..0992683 100644
--- a/src/codegen_backend_x86-64_ops.c
+++ b/src/codegen_backend_x86-64_ops.c
@@ -541,6 +541,11 @@ void host_x86_LDMXCSR(codeblock_t *block, void *p)
         {
                 codegen_addbyte4(block, 0x0f, 0xae, 0x50 | REG_EBP, offset); /*LDMXCSR offset[EBP]*/
         }
+        else if (offset < (1ull << 32))
+        {
+                codegen_addbyte3(block, 0x0f, 0xae, 0x90 | REG_EBP); /*LDMXCSR offset[EBP]*/
+                codegen_addlong(block, offset);
+        }
         else
         {
                 fatal("host_x86_LDMXCSR - out of range %p\n", p);
diff --git a/src/codegen_backend_x86-64_uops.c b/src/codegen_backend_x86-64_uops.c
index 049c626..dd164d6 100644
--- a/src/codegen_backend_x86-64_uops.c
+++ b/src/codegen_backend_x86-64_uops.c
@@ -1576,7 +1576,9 @@ static int codegen_PF2ID(codeblock_t *block, uop_t *uop)
 
         if (REG_IS_Q(dest_size) && REG_IS_Q(src_size_a))
         {
+                host_x86_LDMXCSR(block, &cpu_state.trunc_fp_control);
                 host_x86_CVTPS2DQ_XREG_XREG(block, dest_reg, src_reg_a);
+                host_x86_LDMXCSR(block, &cpu_state.old_fp_control);
         }
         else
                 fatal("PF2ID %02x %02x\n", uop->dest_reg_a_real);
diff --git a/src/codegen_backend_x86.c b/src/codegen_backend_x86.c
index 4a43ff0..82c1d87 100644
--- a/src/codegen_backend_x86.c
+++ b/src/codegen_backend_x86.c
@@ -333,6 +333,7 @@ pclog("  offsetof(codeblock_t, next_2)=%i\n", offsetof(codeblock_t, next_2));
                 : "=m" (cpu_state.old_fp_control2),
                   "=m" (cpu_state.old_fp_control)
         );
+        cpu_state.trunc_fp_control = cpu_state.old_fp_control | 0x6000;
 }
 
 void codegen_set_rounding_mode(int mode)
diff --git a/src/codegen_backend_x86_uops.c b/src/codegen_backend_x86_uops.c
index e53b91d..aa1c885 100644
--- a/src/codegen_backend_x86_uops.c
+++ b/src/codegen_backend_x86_uops.c
@@ -1579,7 +1579,9 @@ static int codegen_PF2ID(codeblock_t *block, uop_t *uop)
 
         if (REG_IS_Q(dest_size) && REG_IS_Q(src_size_a))
         {
+                host_x86_LDMXCSR(block, &cpu_state.trunc_fp_control);
                 host_x86_CVTPS2DQ_XREG_XREG(block, dest_reg, src_reg_a);
+                host_x86_LDMXCSR(block, &cpu_state.old_fp_control);
         }
         else
                 fatal("PF2ID %02x %02x\n", uop->dest_reg_a_real);
diff --git a/src/ibm.h b/src/ibm.h
index e99c232..b587e62 100644
--- a/src/ibm.h
+++ b/src/ibm.h
@@ -181,6 +181,9 @@ struct
         uint32_t old_fp_control, new_fp_control;
 #if defined i386 || defined __i386 || defined __i386__ || defined _X86_
         uint16_t old_fp_control2, new_fp_control2;
+#endif
+#if defined i386 || defined __i386 || defined __i386__ || defined _X86_ || defined __amd64__
+        uint32_t trunc_fp_control;
 #endif
         x86seg seg_cs,seg_ds,seg_es,seg_ss,seg_fs,seg_gs;