target/arm: Replace ARM_FEATURE_VFP4 with isar_feature_aa32_simdfmac

All remaining tests for VFP4 are for fused multiply-add insns.

Since the MVFR1 field is used for both VFP and NEON, move its adjustment
from the !has_neon block to the (!has_vfp && !has_neon) block.

Test for vfp of the appropraite width alongside the test for simdfmac
within translate-vfp.inc.c.  Within disas_neon_data_insn, we have
already tested for ARM_FEATURE_NEON.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20200224222232.13807-10-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 12 insertions, 0 deletions

diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index b94d2a5ace..b29b0eddfc 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -3514,6 +3514,18 @@ static inline bool isar_feature_aa32_fp16_dpconv(const ARMISARegisters *id)
     return FIELD_EX32(id->mvfr1, MVFR1, FPHP) > 1;
 }
 
+/*
+ * Note that this ID register field covers both VFP and Neon FMAC,
+ * so should usually be tested in combination with some other
+ * check that confirms the presence of whichever of VFP or Neon is
+ * relevant, to avoid accidentally enabling a Neon feature on
+ * a VFP-no-Neon core or vice-versa.
+ */
+static inline bool isar_feature_aa32_simdfmac(const ARMISARegisters *id)
+{
+    return FIELD_EX32(id->mvfr1, MVFR1, SIMDFMAC) != 0;
+}
+
 static inline bool isar_feature_aa32_vsel(const ARMISARegisters *id)
 {
     return FIELD_EX32(id->mvfr2, MVFR2, FPMISC) >= 1;