[Qemu-devel] [PATCH 1/7] target-tricore: Add FPU infrastructure

[Bastian Koppelmann]

This patch adds a file for all the FPU related helpers with all the includes,
useful defines, and a function to update the status bits. Additionally it adds
a mask for the rounding mode bits of PSW as well as all the opcodes for the
FPU instructions.

Signed-off-by: Bastian Koppelmann <address@hidden>
---
 target-tricore/Makefile.objs     |  2 +-
 target-tricore/cpu.h             |  4 +-
 target-tricore/fpu_helper.c      | 83 ++++++++++++++++++++++++++++++++++++++++
 target-tricore/tricore-opcodes.h | 18 +++++++++
 4 files changed, 104 insertions(+), 3 deletions(-)
 create mode 100644 target-tricore/fpu_helper.c

diff --git a/target-tricore/Makefile.objs b/target-tricore/Makefile.objs
index 21e820d..7a05670 100644
--- a/target-tricore/Makefile.objs
+++ b/target-tricore/Makefile.objs
@@ -1 +1 @@
-obj-y += translate.o helper.o cpu.o op_helper.o
+obj-y += translate.o helper.o cpu.o op_helper.o fpu_helper.o
diff --git a/target-tricore/cpu.h b/target-tricore/cpu.h
index 5fee376..d85e99f 100644
--- a/target-tricore/cpu.h
+++ b/target-tricore/cpu.h
@@ -183,8 +183,7 @@ struct CPUTriCoreState {
     uint32_t M2CNT;
     uint32_t M3CNT;
     /* Floating Point Registers */
-    /* XXX: */
-
+    float_status fp_status;
     /* QEMU */
     int error_code;
     uint32_t hflags;    /* CPU State */
@@ -217,6 +216,7 @@ struct CPUTriCoreState {
 #define MASK_PSW_GW  0x00000100
 #define MASK_PSW_CDE 0x00000080
 #define MASK_PSW_CDC 0x0000007f
+#define MASK_PSW_FPU_RM 0x3000000
 
 #define MASK_SYSCON_PRO_TEN 0x2
 #define MASK_SYSCON_FCD_SF  0x1
diff --git a/target-tricore/fpu_helper.c b/target-tricore/fpu_helper.c
new file mode 100644
index 0000000..ddf877e
--- /dev/null
+++ b/target-tricore/fpu_helper.c
@@ -0,0 +1,83 @@
+/*
+ *  TriCore emulation for qemu: fpu helper.
+ *
+ *  Copyright (c) 2016 Bastian Koppelmann University of Paderborn
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu/osdep.h"
+#include "cpu.h"
+#include "exec/helper-proto.h"
+
+#define QUIET_NAN 0x7fc00000
+#define ADD_NAN   0x7cf00001
+#define DIV_NAN   0x7fc00008
+#define MUL_NAN   0x7fc00002
+#define FPU_FS PSW_USB_C
+#define FPU_FI PSW_USB_V
+#define FPU_FV PSW_USB_SV
+#define FPU_FZ PSW_USB_AV
+#define FPU_FU PSW_USB_SAV
+
+static inline bool f_is_pos_inf(float32 arg)
+{
+    return !float32_is_neg(arg) && float32_is_infinity(arg);
+}
+
+static inline bool f_is_neg_inf(float32 arg)
+{
+    return float32_is_neg(arg) && float32_is_infinity(arg);
+}
+
+static inline bool f_is_denormal(float32 arg)
+{
+    return float32_is_zero_or_denormal(arg) && !float32_is_zero(arg);
+}
+
+static inline void f_update_psw_flags(CPUTriCoreState *env, bool calc_z)
+{
+    int8_t flags = env->fp_status.float_exception_flags;
+    int32_t some_excp = 0;
+    if (flags & float_flag_invalid) {
+        env->FPU_FI = (flags & float_flag_invalid) << 31;
+        some_excp = 1;
+    }
+    if (flags & float_flag_overflow) {
+        env->FPU_FV = 1 << 31;
+        some_excp = 1;
+    }
+    if (flags & float_flag_underflow || flags & float_flag_output_denormal) {
+        env->FPU_FU = 1 << 31;
+        some_excp = 1;
+    }
+
+    if (calc_z && (flags & float_flag_divbyzero)) {
+        env->FPU_FZ = 1 << 31;
+        some_excp = 1;
+    }
+    if (flags & float_flag_inexact || flags & float_flag_output_denormal) {
+        env->PSW |= 1 << 26;
+        some_excp = 1;
+    }
+    env->FPU_FS = some_excp;
+}
+
+static inline void f_set_flags(CPUTriCoreState *env)
+{
+    set_float_rounding_mode(env->PSW & MASK_PSW_FPU_RM, &env->fp_status);
+    set_flush_inputs_to_zero(1, &env->fp_status);
+    set_flush_to_zero(1, &env->fp_status);
+    set_float_exception_flags(0, &env->fp_status);
+}
diff --git a/target-tricore/tricore-opcodes.h b/target-tricore/tricore-opcodes.h
index 1bfed0c..df666b0 100644
--- a/target-tricore/tricore-opcodes.h
+++ b/target-tricore/tricore-opcodes.h
@@ -1126,6 +1126,20 @@ enum {
     OPC2_32_RR_CRC32                             = 0x03,
     OPC2_32_RR_DIV                               = 0x20,
     OPC2_32_RR_DIV_U                             = 0x21,
+    OPC2_32_RR_MUL_F                             = 0x04,
+    OPC2_32_RR_DIV_F                             = 0x05,
+    OPC2_32_RR_FTOI                              = 0x10,
+    OPC2_32_RR_ITOF                              = 0x14,
+    OPC2_32_RR_CMP_F                             = 0x00,
+    OPC2_32_RR_FTOIZ                             = 0x13,
+    OPC2_32_RR_FTOQ31                            = 0x11,
+    OPC2_32_RR_FTOQ31Z                           = 0x18,
+    OPC2_32_RR_FTOU                              = 0x12,
+    OPC2_32_RR_FTOUZ                             = 0x17,
+    OPC2_32_RR_Q31TOF                            = 0x15,
+    OPC2_32_RR_QSEED_F                           = 0x19,
+    OPC2_32_RR_UPDFL                             = 0x0c,
+    OPC2_32_RR_UTOF                              = 0x16,
 };
 /* OPCM_32_RR_IDIRECT                               */
 enum {
@@ -1209,6 +1223,10 @@ enum {
     OPC2_32_RRR_IXMIN                            = 0x08,
     OPC2_32_RRR_IXMIN_U                          = 0x09,
     OPC2_32_RRR_PACK                             = 0x00,
+    OPC2_32_RRR_ADD_F                            = 0x02,
+    OPC2_32_RRR_SUB_F                            = 0x03,
+    OPC2_32_RRR_MADD_F                           = 0x06,
+    OPC2_32_RRR_MSUB_F                           = 0x07,
 };
 /*
  * RRR1 Format
-- 
2.7.2