Comment 5 for bug 1836078

Revision history for this message
Alex Bennée (ajbennee) wrote : [PATCH for 4.1] target/arm: report ARMv8.2 FP16 for ARM -cpu max

When we converted to using feature bits in 602f6e42cfbf we missed out
the fact (dp && arm_dc_feature(s, ARM_FEATURE_V8)) was supported for
-cpu max configurations. This caused a regression in the GCC test
suite. Fix this by setting the appropriate FP16 bits in mvfr1.FPHP.

Fixes: https://bugs.launchpad.net/qemu/+bug/1836078
Signed-off-by: Alex Bennée <email address hidden>
---
 target/arm/cpu.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index e75a64a25a..0a0a202fe3 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -2452,6 +2452,10 @@ static void arm_max_initfn(Object *obj)
             t = FIELD_DP32(t, ID_ISAR6, SPECRES, 1);
             cpu->isar.id_isar6 = t;

+ t = cpu->isar.mvfr1;
+ t = FIELD_DP32(t, MVFR1, FPHP, 2); /* v8.2 FP16 */
+ cpu->isar.mvfr1 = t;
+
             t = cpu->isar.mvfr2;
             t = FIELD_DP32(t, MVFR2, SIMDMISC, 3); /* SIMD MaxNum */
             t = FIELD_DP32(t, MVFR2, FPMISC, 4); /* FP MaxNum */
--
2.20.1