target/ppc: Fix bugs in VSX_CVT_FP_TO_INT and VSX_CVT_FP_TO_INT2 macros

The patch below fixes a bug in the VSX_CVT_FP_TO_INT and VSX_CVT_FP_TO_INT2
macros in target/ppc/fpu_helper.c where a non-NaN floating point value from the
source vector is incorrectly converted to 0, 0x80000000, or 0x8000000000000000
instead of the expected value if a preceding source floating point value from
the same source vector was a NaN.

The bug in the VSX_CVT_FP_TO_INT and VSX_CVT_FP_TO_INT2 macros in
target/ppc/fpu_helper.c was introduced with commit c3f24257e3c0.

This patch also adds a new vsx_f2i_nan test in tests/tcg/ppc64 that checks that
the VSX xvcvspsxws, xvcvspuxws, xvcvspsxds, xvcvspuxds, xvcvdpsxws, xvcvdpuxws,
xvcvdpsxds, and xvcvdpuxds instructions correctly convert non-NaN floating point
values to integer values if the source vector contains NaN floating point values.

Fixes: c3f24257e3c0 ("target/ppc: Clear fpstatus flags on helpers missing it")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1941
Signed-off-by: John Platts <john_platts@hotmail.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>

2 files changed, 305 insertions, 0 deletions

diff --git a/tests/tcg/ppc64/Makefile.target b/tests/tcg/ppc64/Makefile.target
index 1d08076..ca8b929 100644
--- a/tests/tcg/ppc64/Makefile.target
+++ b/tests/tcg/ppc64/Makefile.target
@@ -16,6 +16,11 @@ PPC64_TESTS=bcdsub non_signalling_xscv
 endif
 $(PPC64_TESTS): CFLAGS += -mpower8-vector
 
+ifneq ($(CROSS_CC_HAS_POWER8_VECTOR),)
+PPC64_TESTS += vsx_f2i_nan
+endif
+vsx_f2i_nan: CFLAGS += -mpower8-vector -I$(SRC_PATH)/include
+
 PPC64_TESTS += mtfsf
 PPC64_TESTS += mffsce
 
diff --git a/tests/tcg/ppc64/vsx_f2i_nan.c b/tests/tcg/ppc64/vsx_f2i_nan.c
new file mode 100644
index 0000000..94b1a4e
--- /dev/null
+++ b/tests/tcg/ppc64/vsx_f2i_nan.c
@@ -0,0 +1,300 @@
+#include <stdio.h>
+#include "qemu/compiler.h"
+
+typedef vector float vsx_float32_vec_t;
+typedef vector double vsx_float64_vec_t;
+typedef vector signed int vsx_int32_vec_t;
+typedef vector unsigned int vsx_uint32_vec_t;
+typedef vector signed long long vsx_int64_vec_t;
+typedef vector unsigned long long vsx_uint64_vec_t;
+
+#define DEFINE_VSX_F2I_FUNC(SRC_T, DEST_T, INSN)                       \
+static inline vsx_##DEST_T##_vec_t                                     \
+    vsx_convert_##SRC_T##_vec_to_##DEST_T##_vec(vsx_##SRC_T##_vec_t v) \
+{                                                                      \
+    vsx_##DEST_T##_vec_t result;                                       \
+    asm(#INSN " %x0, %x1" : "=wa" (result) : "wa" (v));                \
+    return result;                                                     \
+}
+
+DEFINE_VSX_F2I_FUNC(float32, int32, xvcvspsxws)
+DEFINE_VSX_F2I_FUNC(float32, uint32, xvcvspuxws)
+DEFINE_VSX_F2I_FUNC(float32, int64, xvcvspsxds)
+DEFINE_VSX_F2I_FUNC(float32, uint64, xvcvspuxds)
+DEFINE_VSX_F2I_FUNC(float64, int32, xvcvdpsxws)
+DEFINE_VSX_F2I_FUNC(float64, uint32, xvcvdpuxws)
+DEFINE_VSX_F2I_FUNC(float64, int64, xvcvdpsxds)
+DEFINE_VSX_F2I_FUNC(float64, uint64, xvcvdpuxds)
+
+static inline vsx_float32_vec_t vsx_float32_is_nan(vsx_float32_vec_t v)
+{
+    vsx_float32_vec_t abs_v;
+    vsx_float32_vec_t result_mask;
+    const vsx_uint32_vec_t f32_pos_inf_bits = {0x7F800000U, 0x7F800000U,
+                                               0x7F800000U, 0x7F800000U};
+
+    asm("xvabssp %x0, %x1" : "=wa" (abs_v) : "wa" (v));
+    asm("vcmpgtuw %0, %1, %2"
+        : "=v" (result_mask)
+        : "v" (abs_v), "v" (f32_pos_inf_bits));
+    return result_mask;
+}
+
+static inline vsx_float64_vec_t vsx_float64_is_nan(vsx_float64_vec_t v)
+{
+    vsx_float64_vec_t abs_v;
+    vsx_float64_vec_t result_mask;
+    const vsx_uint64_vec_t f64_pos_inf_bits = {0x7FF0000000000000ULL,
+                                               0x7FF0000000000000ULL};
+
+    asm("xvabsdp %x0, %x1" : "=wa" (abs_v) : "wa" (v));
+    asm("vcmpgtud %0, %1, %2"
+        : "=v" (result_mask)
+        : "v" (abs_v), "v" (f64_pos_inf_bits));
+    return result_mask;
+}
+
+#define DEFINE_VSX_BINARY_LOGICAL_OP_INSN(LANE_TYPE, OP_NAME, OP_INSN)    \
+static inline vsx_##LANE_TYPE##_vec_t vsx_##LANE_TYPE##_##OP_NAME(        \
+    vsx_##LANE_TYPE##_vec_t a, vsx_##LANE_TYPE##_vec_t b)                 \
+{                                                                         \
+    vsx_##LANE_TYPE##_vec_t result;                                       \
+    asm(#OP_INSN " %x0, %x1, %x2" : "=wa" (result) : "wa" (a), "wa" (b)); \
+    return result;                                                        \
+}
+
+DEFINE_VSX_BINARY_LOGICAL_OP_INSN(float32, logical_and, xxland)
+DEFINE_VSX_BINARY_LOGICAL_OP_INSN(float64, logical_and, xxland)
+DEFINE_VSX_BINARY_LOGICAL_OP_INSN(int32, logical_and, xxland)
+DEFINE_VSX_BINARY_LOGICAL_OP_INSN(uint32, logical_and, xxland)
+DEFINE_VSX_BINARY_LOGICAL_OP_INSN(int64, logical_and, xxland)
+DEFINE_VSX_BINARY_LOGICAL_OP_INSN(uint64, logical_and, xxland)
+
+DEFINE_VSX_BINARY_LOGICAL_OP_INSN(float32, logical_andc, xxlandc)
+DEFINE_VSX_BINARY_LOGICAL_OP_INSN(float64, logical_andc, xxlandc)
+
+DEFINE_VSX_BINARY_LOGICAL_OP_INSN(float32, logical_or, xxlor)
+DEFINE_VSX_BINARY_LOGICAL_OP_INSN(float64, logical_or, xxlor)
+DEFINE_VSX_BINARY_LOGICAL_OP_INSN(int32, logical_or, xxlor)
+DEFINE_VSX_BINARY_LOGICAL_OP_INSN(uint32, logical_or, xxlor)
+DEFINE_VSX_BINARY_LOGICAL_OP_INSN(int64, logical_or, xxlor)
+DEFINE_VSX_BINARY_LOGICAL_OP_INSN(uint64, logical_or, xxlor)
+
+static inline vsx_int32_vec_t vsx_mask_out_float32_vec_to_int32_vec(
+    vsx_int32_vec_t v)
+{
+    return v;
+}
+static inline vsx_uint32_vec_t vsx_mask_out_float32_vec_to_uint32_vec(
+    vsx_uint32_vec_t v)
+{
+    return v;
+}
+static inline vsx_int64_vec_t vsx_mask_out_float32_vec_to_int64_vec(
+    vsx_int64_vec_t v)
+{
+    return v;
+}
+static inline vsx_uint64_vec_t vsx_mask_out_float32_vec_to_uint64_vec(
+    vsx_uint64_vec_t v)
+{
+    return v;
+}
+
+static inline vsx_int32_vec_t vsx_mask_out_float64_vec_to_int32_vec(
+    vsx_int32_vec_t v)
+{
+#if HOST_BIG_ENDIAN
+    const vsx_int32_vec_t valid_lanes_mask = {-1, 0, -1, 0};
+#else
+    const vsx_int32_vec_t valid_lanes_mask = {0, -1, 0, -1};
+#endif
+
+    return vsx_int32_logical_and(v, valid_lanes_mask);
+}
+
+static inline vsx_uint32_vec_t vsx_mask_out_float64_vec_to_uint32_vec(
+    vsx_uint32_vec_t v)
+{
+    return (vsx_uint32_vec_t)vsx_mask_out_float64_vec_to_int32_vec(
+        (vsx_int32_vec_t)v);
+}
+
+static inline vsx_int64_vec_t vsx_mask_out_float64_vec_to_int64_vec(
+    vsx_int64_vec_t v)
+{
+    return v;
+}
+static inline vsx_uint64_vec_t vsx_mask_out_float64_vec_to_uint64_vec(
+    vsx_uint64_vec_t v)
+{
+    return v;
+}
+
+static inline void print_vsx_float32_vec_elements(FILE *stream,
+                                                  vsx_float32_vec_t vec)
+{
+    fprintf(stream, "%g, %g, %g, %g", (double)vec[0], (double)vec[1],
+            (double)vec[2], (double)vec[3]);
+}
+
+static inline void print_vsx_float64_vec_elements(FILE *stream,
+                                                  vsx_float64_vec_t vec)
+{
+    fprintf(stream, "%.17g, %.17g", vec[0], vec[1]);
+}
+
+static inline void print_vsx_int32_vec_elements(FILE *stream,
+                                                vsx_int32_vec_t vec)
+{
+    fprintf(stream, "%d, %d, %d, %d", vec[0], vec[1], vec[2], vec[3]);
+}
+
+static inline void print_vsx_uint32_vec_elements(FILE *stream,
+                                                 vsx_uint32_vec_t vec)
+{
+    fprintf(stream, "%u, %u, %u, %u", vec[0], vec[1], vec[2], vec[3]);
+}
+
+static inline void print_vsx_int64_vec_elements(FILE *stream,
+                                                vsx_int64_vec_t vec)
+{
+    fprintf(stream, "%lld, %lld", vec[0], vec[1]);
+}
+
+static inline void print_vsx_uint64_vec_elements(FILE *stream,
+                                                 vsx_uint64_vec_t vec)
+{
+    fprintf(stream, "%llu, %llu", vec[0], vec[1]);
+}
+
+#define DEFINE_VSX_ALL_EQ_FUNC(LANE_TYPE, CMP_INSN)                   \
+static inline int vsx_##LANE_TYPE##_all_eq(vsx_##LANE_TYPE##_vec_t a, \
+                                           vsx_##LANE_TYPE##_vec_t b) \
+{                                                                     \
+    unsigned result;                                                  \
+    vsx_##LANE_TYPE##_vec_t is_eq_mask_vec;                           \
+    asm(#CMP_INSN ". %0, %2, %3\n\t"                                  \
+        "mfocrf %1, 2"                                                \
+        : "=v" (is_eq_mask_vec), "=r" (result)                        \
+        : "v" (a), "v" (b)                                            \
+        : "cr6");                                                     \
+    return (int)((result >> 7) & 1u);                                 \
+}
+
+DEFINE_VSX_ALL_EQ_FUNC(int32, vcmpequw)
+DEFINE_VSX_ALL_EQ_FUNC(uint32, vcmpequw)
+DEFINE_VSX_ALL_EQ_FUNC(int64, vcmpequd)
+DEFINE_VSX_ALL_EQ_FUNC(uint64, vcmpequd)
+
+#define DEFINE_VSX_F2I_TEST_FUNC(SRC_T, DEST_T)                          \
+static inline int test_vsx_conv_##SRC_T##_vec_to_##DEST_T##_vec(         \
+    vsx_##SRC_T##_vec_t src_v)                                           \
+{                                                                        \
+    const vsx_##SRC_T##_vec_t is_nan_mask = vsx_##SRC_T##_is_nan(src_v); \
+    const vsx_##SRC_T##_vec_t nan_src_v =                                \
+        vsx_##SRC_T##_logical_and(src_v, is_nan_mask);                   \
+    const vsx_##SRC_T##_vec_t non_nan_src_v =                            \
+        vsx_##SRC_T##_logical_andc(src_v, is_nan_mask);                  \
+                                                                         \
+    const vsx_##DEST_T##_vec_t expected_result =                         \
+        vsx_mask_out_##SRC_T##_vec_to_##DEST_T##_vec(                    \
+            vsx_##DEST_T##_logical_or(                                   \
+                vsx_convert_##SRC_T##_vec_to_##DEST_T##_vec(nan_src_v),  \
+                vsx_convert_##SRC_T##_vec_to_##DEST_T##_vec(             \
+                    non_nan_src_v)));                                    \
+    const vsx_##DEST_T##_vec_t actual_result =                           \
+        vsx_mask_out_##SRC_T##_vec_to_##DEST_T##_vec(                    \
+            vsx_convert_##SRC_T##_vec_to_##DEST_T##_vec(src_v));         \
+    const int test_result =                                              \
+        vsx_##DEST_T##_all_eq(expected_result, actual_result);           \
+                                                                         \
+    if (unlikely(test_result == 0)) {                                    \
+        fputs("FAIL: Conversion of " #SRC_T " vector to " #DEST_T        \
+              " vector failed\n", stdout);                               \
+        fputs("Source values: ", stdout);                                \
+        print_vsx_##SRC_T##_vec_elements(stdout, src_v);                 \
+        fputs("\nExpected result: ", stdout);                            \
+        print_vsx_##DEST_T##_vec_elements(stdout, expected_result);      \
+        fputs("\nActual result: ", stdout);                              \
+        print_vsx_##DEST_T##_vec_elements(stdout, actual_result);        \
+        fputs("\n\n", stdout);                                           \
+    }                                                                    \
+                                                                         \
+    return test_result;                                                  \
+}
+
+
+DEFINE_VSX_F2I_TEST_FUNC(float32, int32)
+DEFINE_VSX_F2I_TEST_FUNC(float32, uint32)
+DEFINE_VSX_F2I_TEST_FUNC(float32, int64)
+DEFINE_VSX_F2I_TEST_FUNC(float32, uint64)
+DEFINE_VSX_F2I_TEST_FUNC(float64, int32)
+DEFINE_VSX_F2I_TEST_FUNC(float64, uint32)
+DEFINE_VSX_F2I_TEST_FUNC(float64, int64)
+DEFINE_VSX_F2I_TEST_FUNC(float64, uint64)
+
+static inline vsx_int32_vec_t vsx_int32_vec_from_mask(int mask)
+{
+    const vsx_int32_vec_t bits_to_test = {1, 2, 4, 8};
+    const vsx_int32_vec_t vec_mask = {mask, mask, mask, mask};
+    vsx_int32_vec_t result;
+
+    asm("vcmpequw %0, %1, %2"
+        : "=v" (result)
+        : "v" (vsx_int32_logical_and(vec_mask, bits_to_test)),
+          "v" (bits_to_test));
+    return result;
+}
+
+static inline vsx_int64_vec_t vsx_int64_vec_from_mask(int mask)
+{
+    const vsx_int64_vec_t bits_to_test = {1, 2};
+    const vsx_int64_vec_t vec_mask = {mask, mask};
+    vsx_int64_vec_t result;
+
+    asm("vcmpequd %0, %1, %2"
+        : "=v" (result)
+        : "v" (vsx_int64_logical_and(vec_mask, bits_to_test)),
+          "v" (bits_to_test));
+    return result;
+}
+
+int main(void)
+{
+    const vsx_float32_vec_t f32_iota1 = {1.0f, 2.0f, 3.0f, 4.0f};
+    const vsx_float64_vec_t f64_iota1 = {1.0, 2.0};
+
+    int num_of_tests_failed = 0;
+
+    for (int i = 0; i < 16; i++) {
+        const vsx_int32_vec_t nan_mask = vsx_int32_vec_from_mask(i);
+        const vsx_float32_vec_t f32_v =
+            vsx_float32_logical_or(f32_iota1, (vsx_float32_vec_t)nan_mask);
+        num_of_tests_failed +=
+            (int)(!test_vsx_conv_float32_vec_to_int32_vec(f32_v));
+        num_of_tests_failed +=
+            (int)(!test_vsx_conv_float32_vec_to_int64_vec(f32_v));
+        num_of_tests_failed +=
+            (int)(!test_vsx_conv_float32_vec_to_uint32_vec(f32_v));
+        num_of_tests_failed +=
+            (int)(!test_vsx_conv_float32_vec_to_uint64_vec(f32_v));
+    }
+
+    for (int i = 0; i < 4; i++) {
+        const vsx_int64_vec_t nan_mask = vsx_int64_vec_from_mask(i);
+        const vsx_float64_vec_t f64_v =
+            vsx_float64_logical_or(f64_iota1, (vsx_float64_vec_t)nan_mask);
+        num_of_tests_failed +=
+            (int)(!test_vsx_conv_float64_vec_to_int32_vec(f64_v));
+        num_of_tests_failed +=
+            (int)(!test_vsx_conv_float64_vec_to_int64_vec(f64_v));
+        num_of_tests_failed +=
+            (int)(!test_vsx_conv_float64_vec_to_uint32_vec(f64_v));
+        num_of_tests_failed +=
+            (int)(!test_vsx_conv_float64_vec_to_uint64_vec(f64_v));
+    }
+
+    printf("%d tests failed\n", num_of_tests_failed);
+    return (int)(num_of_tests_failed != 0);
+}