From 602f6e42cfbfe9278be34e9b91d2ceb695837e02 Mon Sep 17 00:00:00 2001
From: Peter Maydell
Date: Thu, 28 Feb 2019 10:55:16 +0000
Subject: target/arm: Use MVFR1 feature bits to gate A32/T32 FP16 instructions

Instead of gating the A32/T32 FP16 conversion instructions on
the ARM_FEATURE_VFP_FP16 flag, switch to our new approach of
looking at ID register bits. In this case MVFR1 fields FPHP
and SIMDHP indicate the presence of these insns.

This change doesn't alter behaviour for any of our CPUs.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190222170936.13268-2-peter.maydell@linaro.org
---
 target/arm/cpu.h | 37 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 36 insertions(+), 1 deletion(-)

(limited to 'target/arm/cpu.h')

diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 1eea1a408b..36ea3b5856 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -1730,6 +1730,27 @@ FIELD(ID_DFR0, MPROFDBG, 20, 4)
 FIELD(ID_DFR0, PERFMON, 24, 4)
 FIELD(ID_DFR0, TRACEFILT, 28, 4)
 
+FIELD(MVFR0, SIMDREG, 0, 4)
+FIELD(MVFR0, FPSP, 4, 4)
+FIELD(MVFR0, FPDP, 8, 4)
+FIELD(MVFR0, FPTRAP, 12, 4)
+FIELD(MVFR0, FPDIVIDE, 16, 4)
+FIELD(MVFR0, FPSQRT, 20, 4)
+FIELD(MVFR0, FPSHVEC, 24, 4)
+FIELD(MVFR0, FPROUND, 28, 4)
+
+FIELD(MVFR1, FPFTZ, 0, 4)
+FIELD(MVFR1, FPDNAN, 4, 4)
+FIELD(MVFR1, SIMDLS, 8, 4)
+FIELD(MVFR1, SIMDINT, 12, 4)
+FIELD(MVFR1, SIMDSP, 16, 4)
+FIELD(MVFR1, SIMDHP, 20, 4)
+FIELD(MVFR1, FPHP, 24, 4)
+FIELD(MVFR1, SIMDFMAC, 28, 4)
+
+FIELD(MVFR2, SIMDMISC, 0, 4)
+FIELD(MVFR2, FPMISC, 4, 4)
+
 QEMU_BUILD_BUG_ON(ARRAY_SIZE(((ARMCPU *)0)->ccsidr) <= R_V7M_CSSELR_INDEX_MASK);
 
 /* If adding a feature bit which corresponds to a Linux ELF
@@ -1747,7 +1768,6 @@ enum arm_features {
     ARM_FEATURE_THUMB2,
     ARM_FEATURE_PMSA,   /* no MMU; may have Memory Protection Unit */
     ARM_FEATURE_VFP3,
-    ARM_FEATURE_VFP_FP16,
     ARM_FEATURE_NEON,
     ARM_FEATURE_M, /* Microcontroller profile.  */
     ARM_FEATURE_OMAPCP, /* OMAP specific CP15 ops handling.  */
@@ -3293,6 +3313,21 @@ static inline bool isar_feature_aa32_fp16_arith(const ARMISARegisters *id)
     return FIELD_EX64(id->id_aa64pfr0, ID_AA64PFR0, FP) == 1;
 }
 
+/*
+ * We always set the FP and SIMD FP16 fields to indicate identical
+ * levels of support (assuming SIMD is implemented at all), so
+ * we only need one set of accessors.
+ */
+static inline bool isar_feature_aa32_fp16_spconv(const ARMISARegisters *id)
+{
+    return FIELD_EX64(id->mvfr1, MVFR1, FPHP) > 0;
+}
+
+static inline bool isar_feature_aa32_fp16_dpconv(const ARMISARegisters *id)
+{
+    return FIELD_EX64(id->mvfr1, MVFR1, FPHP) > 1;
+}
+
 /*
  * 64-bit feature tests via id registers.
  */
-- 
cgit v1.2.3-55-g7522