[Qemu-devel] [PATCH 069/111] m68k: add fetox and flogn

[Bryce Lanham]

From: Laurent Vivier <address@hidden>

Signed-off-by: Laurent Vivier <address@hidden>
---
 fpu/softfloat.h         |    2 ++
 target-m68k/helper.c    |   38 ++++++++++++++++++++++++++++++++++++--
 target-m68k/helpers.h   |    2 ++
 target-m68k/translate.c |    6 ++++++
 tests/m68k/Makefile     |    2 +-
 tests/m68k/fetox.S      |    8 ++++++++
 tests/m68k/flogn.S      |    8 ++++++++
 7 files changed, 63 insertions(+), 3 deletions(-)
 create mode 100644 tests/m68k/fetox.S
 create mode 100644 tests/m68k/flogn.S

diff --git a/fpu/softfloat.h b/fpu/softfloat.h
index 3bb7d8f..f6d5fce 100644
--- a/fpu/softfloat.h
+++ b/fpu/softfloat.h
@@ -532,6 +532,8 @@ INLINE int floatx80_is_any_nan(floatx80 a)
 #define floatx80_pi make_floatx80(0x4000, 0xc90fdaa22168c235LL)
 #define floatx80_half make_floatx80(0x3ffe, 0x8000000000000000LL)
 #define floatx80_infinity make_floatx80(0x7fff, 0x8000000000000000LL)
+#define floatx80_e make_floatx80(0x4000, 0xadf85458a2bb4a9aULL)
+#define floatx80_log2e make_floatx80(0x3fff, 0xb8aa3b295c17f0bcULL)
 
 /*----------------------------------------------------------------------------
 | The pattern for a default generated extended double-precision NaN.
diff --git a/target-m68k/helper.c b/target-m68k/helper.c
index 77d88e7..f67bfba 100644
--- a/target-m68k/helper.c
+++ b/target-m68k/helper.c
@@ -997,8 +997,8 @@ static const floatx80 fpu_rom[128] = {
     [0x00] = floatx80_pi,                                       /* Pi */
 
     [0x0b] = { .high = 0x3ffd, .low = 0x9a209a84fbcff798ULL },  /* Log10(2) */
-    [0x0c] = { .high = 0x4000, .low = 0xadf85458a2bb4a9aULL },  /* e        */
-    [0x0d] = { .high = 0x3fff, .low = 0xb8aa3b295c17f0bcULL },  /* Log2(e)  */
+    [0x0c] = floatx80_e,                                        /* e        */
+    [0x0d] = floatx80_log2e,                                    /* Log2(e)  */
     [0x0e] = { .high = 0x3ffd, .low = 0xde5bd8a937287195ULL },  /* Log10(e) */
     [0x0f] = floatx80_zero,                                     /* Zero     */
 
@@ -1255,6 +1255,40 @@ void HELPER(sqrt_FP0)(CPUState *env)
     floatx80_to_FP0(env, res);
 }
 
+void HELPER(ln_FP0)(CPUState *env)
+{
+    float64 f, log2;
+    floatx80 res;
+
+    /* ln(x) = log2(x) / log2(e) */
+
+    DBG_FPU("ln_FP0\n");
+
+    f = floatx80_to_float64(FP0_to_floatx80(env), &env->fp_status);
+
+    log2 = float64_log2(f, &env->fp_status);
+    res = floatx80_div(float64_to_floatx80(log2, &env->fp_status),
+                       floatx80_log2e, &env->fp_status);
+
+    floatx80_to_FP0(env, res);
+}
+
+void HELPER(exp_FP0)(CPUState *env)
+{
+    floatx80 f;
+    float32 res;
+
+    /* exp(x) = exp2(x * log2(e)) */
+
+    DBG_FPU("exp_FP0\n");
+
+    f = floatx80_mul(FP0_to_floatx80(env), floatx80_log2e, &env->fp_status);
+    res = float32_exp2(floatx80_to_float32(f, &env->fp_status),
+                       &env->fp_status);
+
+    floatx80_to_FP0(env, float32_to_floatx80(res, &env->fp_status));
+}
+
 void HELPER(abs_FP0)(CPUState *env)
 {
     floatx80 res;
diff --git a/target-m68k/helpers.h b/target-m68k/helpers.h
index f6578ee..53ab1a9 100644
--- a/target-m68k/helpers.h
+++ b/target-m68k/helpers.h
@@ -65,6 +65,8 @@ DEF_HELPER_2(const_FP0, void, env, i32)
 DEF_HELPER_1(iround_FP0, void, env)
 DEF_HELPER_1(itrunc_FP0, void, env)
 DEF_HELPER_1(sqrt_FP0, void, env)
+DEF_HELPER_1(exp_FP0, void, env)
+DEF_HELPER_1(ln_FP0, void, env)
 DEF_HELPER_1(abs_FP0, void, env)
 DEF_HELPER_1(chs_FP0, void, env)
 DEF_HELPER_1(getexp_FP0, void, env)
diff --git a/target-m68k/translate.c b/target-m68k/translate.c
index fb12f3b..1901b1b 100644
--- a/target-m68k/translate.c
+++ b/target-m68k/translate.c
@@ -3641,6 +3641,12 @@ DISAS_INSN(fpu)
     case 4: case 0x41: case 0x45: /* fsqrt */
         gen_helper_sqrt_FP0(cpu_env);
         break;
+    case 0x10:                       /* fetox */
+        gen_helper_exp_FP0(cpu_env);
+        break;
+    case 0x14:                       /* flogn */
+        gen_helper_ln_FP0(cpu_env);
+        break;
     case 0x18: case 0x58: case 0x5c: /* fabs */
         gen_helper_abs_FP0(cpu_env);
         break;
diff --git a/tests/m68k/Makefile b/tests/m68k/Makefile
index 28a998f..8e90986 100644
--- a/tests/m68k/Makefile
+++ b/tests/m68k/Makefile
@@ -1,4 +1,4 @@
-TESTS=fmovecr fmove fmovem fsub fdiv fmul fabs fgetexp fscale
+TESTS=fmovecr fmove fmovem fsub fdiv fmul fabs fgetexp fscale flogn fetox
 
 all: $(TESTS)
 
diff --git a/tests/m68k/fetox.S b/tests/m68k/fetox.S
new file mode 100644
index 0000000..302072b
--- /dev/null
+++ b/tests/m68k/fetox.S
@@ -0,0 +1,8 @@
+       .include "trap.i"
+
+       .text
+       .globl _start
+_start:
+       fmove.l #1,%fp0         // 1
+       fetox.x %fp0,%fp0       // e
+       exit 0
diff --git a/tests/m68k/flogn.S b/tests/m68k/flogn.S
new file mode 100644
index 0000000..a27835e
--- /dev/null
+++ b/tests/m68k/flogn.S
@@ -0,0 +1,8 @@
+       .include "trap.i"
+
+       .text
+       .globl _start
+_start:
+       fmovecr.x #0x0C,%fp0    // e
+       flogn.x %fp0,%fp0       // 1
+       exit 0
-- 
1.7.2.3