tests/tcg/arm: add fcvt test cases for AArch32/64

This runs through the usual float to float conversions and crucially
also runs with ARM Alternative Half Precision Format.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

1 files changed, 458 insertions, 0 deletions

diff --git a/tests/tcg/arm/fcvt.c b/tests/tcg/arm/fcvt.c
new file mode 100644
index 0000000..617626b
--- /dev/null
+++ b/tests/tcg/arm/fcvt.c
@@ -0,0 +1,458 @@
+/*
+ * Test Floating Point Conversion
+ */
+
+/* we want additional float type definitions */
+#define __STDC_WANT_IEC_60559_BFP_EXT__
+#define __STDC_WANT_IEC_60559_TYPES_EXT__
+
+#include <stdio.h>
+#include <inttypes.h>
+#include <math.h>
+#include <float.h>
+#include <fenv.h>
+
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+
+static char flag_str[256];
+
+static char *get_flag_state(int flags)
+{
+    if (flags) {
+        snprintf(flag_str, sizeof(flag_str), "%s %s %s %s %s",
+                 flags & FE_OVERFLOW ? "OVERFLOW" : "",
+                 flags & FE_UNDERFLOW ? "UNDERFLOW" : "",
+                 flags & FE_DIVBYZERO ? "DIV0" : "",
+                 flags & FE_INEXACT ? "INEXACT" : "",
+                 flags & FE_INVALID ? "INVALID" : "");
+    } else {
+        snprintf(flag_str, sizeof(flag_str), "OK");
+    }
+
+    return flag_str;
+}
+
+static void print_double_number(int i, double num)
+{
+    uint64_t double_as_hex = *(uint64_t *) &num;
+    int flags = fetestexcept(FE_ALL_EXCEPT);
+    char *fstr = get_flag_state(flags);
+
+    printf("%02d DOUBLE: %02.20e / %#020" PRIx64 " (%#x => %s)\n",
+           i, num, double_as_hex, flags, fstr);
+}
+
+static void print_single_number(int i, float num)
+{
+    uint32_t single_as_hex = *(uint32_t *) &num;
+    int flags = fetestexcept(FE_ALL_EXCEPT);
+    char *fstr = get_flag_state(flags);
+
+    printf("%02d SINGLE: %02.20e / %#010x  (%#x => %s)\n",
+           i, num, single_as_hex, flags, fstr);
+}
+
+static void print_half_number(int i, uint16_t num)
+{
+    int flags = fetestexcept(FE_ALL_EXCEPT);
+    char *fstr = get_flag_state(flags);
+
+    printf("%02d   HALF: %#04x  (%#x => %s)\n",
+           i, num, flags, fstr);
+}
+
+static void print_int64(int i, int64_t num)
+{
+    uint64_t int64_as_hex = *(uint64_t *) &num;
+    int flags = fetestexcept(FE_ALL_EXCEPT);
+    char *fstr = get_flag_state(flags);
+
+    printf("%02d   INT64: %20" PRId64 "/%#020" PRIx64 " (%#x => %s)\n",
+           i, num, int64_as_hex, flags, fstr);
+}
+
+#ifndef SNANF
+/* Signaling NaN macros, if supported.  */
+# if __GNUC_PREREQ(3, 3)
+#  define SNANF (__builtin_nansf (""))
+#  define SNAN (__builtin_nans (""))
+#  define SNANL (__builtin_nansl (""))
+# endif
+#endif
+
+float single_numbers[] = { -SNANF,
+                           -NAN,
+                           -INFINITY,
+                           -FLT_MAX,
+                           -1.111E+31,
+                           -1.111E+30,
+                           -1.08700982e-12,
+                           -1.78051176e-20,
+                           -FLT_MIN,
+                           0.0,
+                           FLT_MIN,
+                           2.98023224e-08,
+                           5.96046E-8, /* min positive FP16 subnormal */
+                           6.09756E-5, /* max subnormal FP16 */
+                           6.10352E-5, /* min positive normal FP16 */
+                           1.0,
+                           1.0009765625, /* smallest float after 1.0 FP16 */
+                           2.0,
+                           M_E, M_PI,
+                           65503.0,
+                           65504.0, /* max FP16 */
+                           65505.0,
+                           131007.0,
+                           131008.0, /* max AFP */
+                           131009.0,
+                           1.111E+30,
+                           FLT_MAX,
+                           INFINITY,
+                           NAN,
+                           SNANF };
+
+static void convert_single_to_half(void)
+{
+    int i;
+
+    printf("Converting single-precision to half-precision\n");
+
+    for (i = 0; i < ARRAY_SIZE(single_numbers); ++i) {
+        float input = single_numbers[i];
+
+        feclearexcept(FE_ALL_EXCEPT);
+
+        print_single_number(i, input);
+#if defined(__arm__)
+        uint32_t output;
+        asm("vcvtb.f16.f32 %0, %1" : "=t" (output) : "x" (input));
+#else
+        uint16_t output;
+        asm("fcvt %h0, %s1" : "=w" (output) : "x" (input));
+#endif
+        print_half_number(i, output);
+    }
+}
+
+static void convert_single_to_double(void)
+{
+    int i;
+
+    printf("Converting single-precision to double-precision\n");
+
+    for (i = 0; i < ARRAY_SIZE(single_numbers); ++i) {
+        float input = single_numbers[i];
+        /* uint64_t output; */
+        double output;
+
+        feclearexcept(FE_ALL_EXCEPT);
+
+        print_single_number(i, input);
+#if defined(__arm__)
+        asm("vcvt.f64.f32 %P0, %1" : "=w" (output) : "t" (input));
+#else
+        asm("fcvt %d0, %s1" : "=w" (output) : "x" (input));
+#endif
+        print_double_number(i, output);
+    }
+}
+
+static void convert_single_to_integer(void)
+{
+    int i;
+
+    printf("Converting single-precision to integer\n");
+
+    for (i = 0; i < ARRAY_SIZE(single_numbers); ++i) {
+        float input = single_numbers[i];
+        int64_t output;
+
+        feclearexcept(FE_ALL_EXCEPT);
+
+        print_single_number(i, input);
+#if defined(__arm__)
+        /* asm("vcvt.s32.f32 %s0, %s1" : "=t" (output) : "t" (input)); */
+        output = input;
+#else
+        asm("fcvtzs %0, %s1" : "=r" (output) : "w" (input));
+#endif
+        print_int64(i, output);
+    }
+}
+
+/* This allows us to initialise some doubles as pure hex */
+typedef union {
+    double d;
+    uint64_t h;
+} test_doubles;
+
+test_doubles double_numbers[] = {
+    {SNAN},
+    {-NAN},
+    {-INFINITY},
+    {-DBL_MAX},
+    {-FLT_MAX-1.0},
+    {-FLT_MAX},
+    {-1.111E+31},
+    {-1.111E+30}, /* half prec */
+    {-2.0}, {-1.0},
+    {-DBL_MIN},
+    {-FLT_MIN},
+    {0.0},
+    {FLT_MIN},
+    {2.98023224e-08},
+    {5.96046E-8}, /* min positive FP16 subnormal */
+    {6.09756E-5}, /* max subnormal FP16 */
+    {6.10352E-5}, /* min positive normal FP16 */
+    {1.0},
+    {1.0009765625}, /* smallest float after 1.0 FP16 */
+    {DBL_MIN},
+    {1.3789972848607228e-308},
+    {1.4914738736681624e-308},
+    {1.0}, {2.0},
+    {M_E}, {M_PI},
+    {65503.0},
+    {65504.0}, /* max FP16 */
+    {65505.0},
+    {131007.0},
+    {131008.0}, /* max AFP */
+    {131009.0},
+    {.h = 0x41dfffffffc00000 }, /* to int = 0x7fffffff */
+    {FLT_MAX},
+    {FLT_MAX + 1.0},
+    {DBL_MAX},
+    {INFINITY},
+    {NAN},
+    {.h = 0x7ff0000000000001}, /* SNAN */
+    {SNAN},
+};
+
+static void convert_double_to_half(void)
+{
+    int i;
+
+    printf("Converting double-precision to half-precision\n");
+
+    for (i = 0; i < ARRAY_SIZE(double_numbers); ++i) {
+        double input = double_numbers[i].d;
+        uint16_t output;
+
+        feclearexcept(FE_ALL_EXCEPT);
+
+        print_double_number(i, input);
+
+        /* as we don't have _Float16 support */
+#if defined(__arm__)
+        /* asm("vcvtb.f16.f64 %0, %P1" : "=t" (output) : "x" (input)); */
+        output = input;
+#else
+        asm("fcvt %h0, %d1" : "=w" (output) : "x" (input));
+#endif
+        print_half_number(i, output);
+    }
+}
+
+static void convert_double_to_single(void)
+{
+    int i;
+
+    printf("Converting double-precision to single-precision\n");
+
+    for (i = 0; i < ARRAY_SIZE(double_numbers); ++i) {
+        double input = double_numbers[i].d;
+        uint32_t output;
+
+        feclearexcept(FE_ALL_EXCEPT);
+
+        print_double_number(i, input);
+
+#if defined(__arm__)
+        asm("vcvt.f32.f64 %0, %P1" : "=w" (output) : "x" (input));
+#else
+        asm("fcvt %s0, %d1" : "=w" (output) : "x" (input));
+#endif
+
+        print_single_number(i, output);
+    }
+}
+
+static void convert_double_to_integer(void)
+{
+    int i;
+
+    printf("Converting double-precision to integer\n");
+
+    for (i = 0; i < ARRAY_SIZE(double_numbers); ++i) {
+        double input = double_numbers[i].d;
+        int64_t output;
+
+        feclearexcept(FE_ALL_EXCEPT);
+
+        print_double_number(i, input);
+#if defined(__arm__)
+        /* asm("vcvt.s32.f32 %s0, %s1" : "=t" (output) : "t" (input)); */
+        output = input;
+#else
+        asm("fcvtzs %0, %d1" : "=r" (output) : "w" (input));
+#endif
+        print_int64(i, output);
+    }
+}
+
+/* no handy defines for these numbers */
+uint16_t half_numbers[] = {
+    0xffff, /* -NaN / AHP -Max */
+    0xfcff, /* -NaN / AHP */
+    0xfc01, /* -NaN / AHP */
+    0xfc00, /* -Inf */
+    0xfbff, /* -Max */
+    0xc000, /* -2 */
+    0xbc00, /* -1 */
+    0x8001, /* -MIN subnormal */
+    0x8000, /* -0 */
+    0x0000, /* +0 */
+    0x0001, /* MIN subnormal */
+    0x3c00, /* 1 */
+    0x7bff, /* Max */
+    0x7c00, /* Inf */
+    0x7c01, /* NaN / AHP */
+    0x7cff, /* NaN / AHP */
+    0x7fff, /* NaN / AHP +Max*/
+};
+
+static void convert_half_to_double(void)
+{
+    int i;
+
+    printf("Converting half-precision to double-precision\n");
+
+    for (i = 0; i < ARRAY_SIZE(half_numbers); ++i) {
+        uint16_t input = half_numbers[i];
+        double output;
+
+        feclearexcept(FE_ALL_EXCEPT);
+
+        print_half_number(i, input);
+#if defined(__arm__)
+        /* asm("vcvtb.f64.f16 %P0, %1" : "=w" (output) : "t" (input)); */
+        output = input;
+#else
+        asm("fcvt %d0, %h1" : "=w" (output) : "x" (input));
+#endif
+        print_double_number(i, output);
+    }
+}
+
+static void convert_half_to_single(void)
+{
+    int i;
+
+    printf("Converting half-precision to single-precision\n");
+
+    for (i = 0; i < ARRAY_SIZE(half_numbers); ++i) {
+        uint16_t input = half_numbers[i];
+        float output;
+
+        feclearexcept(FE_ALL_EXCEPT);
+
+        print_half_number(i, input);
+#if defined(__arm__)
+        asm("vcvtb.f32.f16 %0, %1" : "=w" (output) : "x" ((uint32_t)input));
+#else
+        asm("fcvt %s0, %h1" : "=w" (output) : "x" (input));
+#endif
+        print_single_number(i, output);
+    }
+}
+
+static void convert_half_to_integer(void)
+{
+    int i;
+
+    printf("Converting half-precision to integer\n");
+
+    for (i = 0; i < ARRAY_SIZE(half_numbers); ++i) {
+        uint16_t input = half_numbers[i];
+        int64_t output;
+
+        feclearexcept(FE_ALL_EXCEPT);
+
+        print_half_number(i, input);
+#if defined(__arm__)
+        /* asm("vcvt.s32.f16 %0, %1" : "=t" (output) : "t" (input)); v8.2*/
+        output = input;
+#else
+        asm("fcvt %s0, %h1" : "=w" (output) : "x" (input));
+#endif
+        print_int64(i, output);
+    }
+}
+
+typedef struct {
+    int flag;
+    char *desc;
+} float_mapping;
+
+float_mapping round_flags[] = {
+    { FE_TONEAREST, "to nearest" },
+    { FE_UPWARD, "upwards" },
+    { FE_DOWNWARD, "downwards" },
+    { FE_TOWARDZERO, "to zero" }
+};
+
+int main(int argc, char *argv[argc])
+{
+    int i;
+
+    printf("#### Enabling IEEE Half Precision\n");
+
+    for (i = 0; i < ARRAY_SIZE(round_flags); ++i) {
+        fesetround(round_flags[i].flag);
+        printf("### Rounding %s\n", round_flags[i].desc);
+        convert_single_to_half();
+        convert_single_to_double();
+        convert_double_to_half();
+        convert_double_to_single();
+        convert_half_to_single();
+        convert_half_to_double();
+    }
+
+    /* convert to integer */
+    convert_single_to_integer();
+    convert_double_to_integer();
+    convert_half_to_integer();
+
+    /* And now with ARM alternative FP16 */
+#if defined(__arm__)
+    /* See glibc sysdeps/arm/fpu_control.h */
+    asm("mrc p10, 7, r1, cr1, cr0, 0\n\t"
+        "orr r1, r1, %[flags]\n\t"
+        "mcr p10, 7, r1, cr1, cr0, 0\n\t"
+        : /* no output */ : [flags] "n" (1 << 26) : "r1" );
+#else
+    asm("mrs x1, fpcr\n\t"
+        "orr x1, x1, %[flags]\n\t"
+        "msr fpcr, x1\n\t"
+        : /* no output */ : [flags] "n" (1 << 26) : "x1" );
+#endif
+
+    printf("#### Enabling ARM Alternative Half Precision\n");
+
+    for (i = 0; i < ARRAY_SIZE(round_flags); ++i) {
+        fesetround(round_flags[i].flag);
+        printf("### Rounding %s\n", round_flags[i].desc);
+        convert_single_to_half();
+        convert_single_to_double();
+        convert_double_to_half();
+        convert_double_to_single();
+        convert_half_to_single();
+        convert_half_to_double();
+    }
+
+    /* convert to integer */
+    convert_single_to_integer();
+    convert_double_to_integer();
+    convert_half_to_integer();
+
+    return 0;
+}