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From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: peter.maydell@linaro.org
Subject: [PATCH 15/19] linux-user/arm: Replace ARM_FEATURE_VFP* tests for HWCAP
Date: Fri, 14 Feb 2020 10:15:43 -0800	[thread overview]
Message-ID: <20200214181547.21408-16-richard.henderson@linaro.org> (raw)
In-Reply-To: <20200214181547.21408-1-richard.henderson@linaro.org>

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>
---
 linux-user/elfload.c | 24 +++++++++++++++---------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index f3080a1635..c52c814a2e 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -468,22 +468,28 @@ 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(arm_div, ARM_HWCAP_ARM_IDIVA);
     GET_FEATURE_ID(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.
+    /*
+     * Note that none of QEMU's cpus have double precision without single
+     * precision support in VFP, so only test the single precision field.
      */
-    GET_FEATURE(ARM_FEATURE_VFP3, ARM_HWCAP_ARM_VFPD32);
-    GET_FEATURE(ARM_FEATURE_LPAE, ARM_HWCAP_ARM_LPAE);
+    GET_FEATURE_ID(aa32_fpsp_v2, ARM_HWCAP_ARM_VFP);
+    if (cpu_isar_feature(aa32_fpsp_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;
 }
-- 
2.20.1



  parent reply	other threads:[~2020-02-14 18:21 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-14 18:15 [PATCH 00/19] target/arm: vfp feature and decodetree cleanup Richard Henderson
2020-02-14 18:15 ` [PATCH 01/19] target/arm: Fix field extract from MVFR[0-2] Richard Henderson
2020-02-14 18:29   ` Philippe Mathieu-Daudé
2020-02-14 18:35   ` Peter Maydell
2020-02-14 18:15 ` [PATCH 02/19] target/arm: Rename isar_feature_aa32_simd_r32 Richard Henderson
2020-02-14 18:50   ` Philippe Mathieu-Daudé
2020-02-21 15:58   ` Peter Maydell
2020-02-14 18:15 ` [PATCH 03/19] target/arm: Use isar_feature_aa32_simd_r32 more places Richard Henderson
2020-02-21 16:02   ` Peter Maydell
2020-02-14 18:15 ` [PATCH 04/19] target/arm: Set MVFR0.FPSP for ARMv5 cpus Richard Henderson
2020-02-21 16:02   ` Peter Maydell
2020-02-14 18:15 ` [PATCH 05/19] target/arm: Add isar_feature_aa32_simd_r16 Richard Henderson
2020-02-21 16:01   ` Peter Maydell
2020-02-14 18:15 ` [PATCH 06/19] target/arm: Rename isar_feature_aa32_fpdp_v2 Richard Henderson
2020-02-14 18:51   ` Philippe Mathieu-Daudé
2020-02-14 18:15 ` [PATCH 07/19] target/arm: Add isar_feature_aa32_{fpsp_v2, fpsp_v3, fpdp_v3} Richard Henderson
2020-02-21 16:03   ` Peter Maydell
2020-02-14 18:15 ` [PATCH 08/19] target/arm: Perform fpdp_v2 check first Richard Henderson
2020-02-21 16:04   ` Peter Maydell
2020-02-14 18:15 ` [PATCH 09/19] target/arm: Replace ARM_FEATURE_VFP3 checks with fp{sp, dp}_v3 Richard Henderson
2020-02-21 16:05   ` Peter Maydell
2020-02-14 18:15 ` [PATCH 10/19] target/arm: Add missing checks for fpsp_v2 Richard Henderson
2020-02-21 16:05   ` Peter Maydell
2020-02-14 18:15 ` [PATCH 11/19] target/arm: Replace ARM_FEATURE_VFP4 with isar_feature_aa32_simdfmac Richard Henderson
2020-02-20 16:37   ` Peter Maydell
2020-02-20 16:41     ` Peter Maydell
2020-02-20 17:55     ` Richard Henderson
2020-02-14 18:15 ` [PATCH 12/19] target/arm: Remove ARM_FEATURE_VFP check from disas_vfp_insn Richard Henderson
2020-02-20 17:19   ` Peter Maydell
2020-02-14 18:15 ` [PATCH 13/19] target/arm: Move VLLDM and VLSTM to vfp.decode Richard Henderson
2020-02-20 17:02   ` Peter Maydell
2020-02-14 18:15 ` [PATCH 14/19] target/arm: Move the vfp decodetree calls next to the base isa Richard Henderson
2020-02-20 17:16   ` Peter Maydell
2020-02-14 18:15 ` Richard Henderson [this message]
2020-02-20 17:32   ` [PATCH 15/19] linux-user/arm: Replace ARM_FEATURE_VFP* tests for HWCAP Peter Maydell
2020-02-14 18:15 ` [PATCH 16/19] target/arm: Remove ARM_FEATURE_VFP* Richard Henderson
2020-02-20 17:33   ` Peter Maydell
2020-02-14 18:15 ` [PATCH 17/19] target/arm: Add formats for some vfp 2 and 3-register insns Richard Henderson
2020-02-20 17:40   ` Peter Maydell
2020-02-14 18:15 ` [PATCH 18/19] target/arm: Split VFM decode Richard Henderson
2020-02-20 17:45   ` Peter Maydell
2020-02-14 18:15 ` [PATCH 19/19] target/arm: Split VMINMAXNM decode Richard Henderson
2020-02-20 17:49   ` Peter Maydell
2020-02-14 20:11 ` [PATCH 00/19] target/arm: vfp feature and decodetree cleanup no-reply
2020-02-20 17:52 ` Peter Maydell

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