linux-user/arm: Replace ARM_FEATURE_VFP* tests for HWCAP

Use isar feature tests instead of feature bit tests.

Although none of QEMUs current cpus have VFPv3 without D32,
replace the large comment explaining why with one line that
sets ARM_HWCAP_ARM_VFPv3D16 under the correct conditions.
Mirror the test sequence used in the linux kernel.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20200224222232.13807-14-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index b1a895f24cef36dbc14a0940bfc63151bb877b54..86cda127b78fd25764cae5ca32f00d641c3eaac6 100644 (file)
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -468,22 +468,25 @@ static uint32_t get_elf_hwcap(void)
 
     /* EDSP is in v5TE and above, but all our v5 CPUs are v5TE */
     GET_FEATURE(ARM_FEATURE_V5, ARM_HWCAP_ARM_EDSP);
-    GET_FEATURE(ARM_FEATURE_VFP, ARM_HWCAP_ARM_VFP);
     GET_FEATURE(ARM_FEATURE_IWMMXT, ARM_HWCAP_ARM_IWMMXT);
     GET_FEATURE(ARM_FEATURE_THUMB2EE, ARM_HWCAP_ARM_THUMBEE);
     GET_FEATURE(ARM_FEATURE_NEON, ARM_HWCAP_ARM_NEON);
-    GET_FEATURE(ARM_FEATURE_VFP3, ARM_HWCAP_ARM_VFPv3);
     GET_FEATURE(ARM_FEATURE_V6K, ARM_HWCAP_ARM_TLS);
-    GET_FEATURE(ARM_FEATURE_VFP4, ARM_HWCAP_ARM_VFPv4);
+    GET_FEATURE(ARM_FEATURE_LPAE, ARM_HWCAP_ARM_LPAE);
     GET_FEATURE_ID(aa32_arm_div, ARM_HWCAP_ARM_IDIVA);
     GET_FEATURE_ID(aa32_thumb_div, ARM_HWCAP_ARM_IDIVT);
-    /* All QEMU's VFPv3 CPUs have 32 registers, see VFP_DREG in translate.c.
-     * Note that the ARM_HWCAP_ARM_VFPv3D16 bit is always the inverse of
-     * ARM_HWCAP_ARM_VFPD32 (and so always clear for QEMU); it is unrelated
-     * to our VFP_FP16 feature bit.
-     */
-    GET_FEATURE(ARM_FEATURE_VFP3, ARM_HWCAP_ARM_VFPD32);
-    GET_FEATURE(ARM_FEATURE_LPAE, ARM_HWCAP_ARM_LPAE);
+    GET_FEATURE_ID(aa32_vfp, ARM_HWCAP_ARM_VFP);
+
+    if (cpu_isar_feature(aa32_fpsp_v3, cpu) ||
+        cpu_isar_feature(aa32_fpdp_v3, cpu)) {
+        hwcaps |= ARM_HWCAP_ARM_VFPv3;
+        if (cpu_isar_feature(aa32_simd_r32, cpu)) {
+            hwcaps |= ARM_HWCAP_ARM_VFPD32;
+        } else {
+            hwcaps |= ARM_HWCAP_ARM_VFPv3D16;
+        }
+    }
+    GET_FEATURE_ID(aa32_simdfmac, ARM_HWCAP_ARM_VFPv4);
 
     return hwcaps;
 }