File target-arm-Introduce-PREDDESC-field-defi.patch of Package qemu.20747

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File target-arm-Introduce-PREDDESC-field-defi.patch of Package qemu.20747

From: Richard Henderson <richard.henderson@linaro.org>
Date: Tue, 12 Jan 2021 20:26:47 -1000
Subject: target/arm: Introduce PREDDESC field definitions

Git-commit: b64ee454a4a086ed459bcda4c0bbb54e197841e4

SVE predicate operations cannot use the "usual" simd_desc
encoding, because the lengths are not a multiple of 8.
But we were abusing the SIMD_* fields to store values anyway.
This abuse broke when SIMD_OPRSZ_BITS was modified in e2e7168a214.

Introduce a new set of field definitions for exclusive use
of predicates, so that it is obvious what kind of predicate
we are manipulating.  To be used in future patches.

Cc: qemu-stable@nongnu.org
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210113062650.593824-2-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Bruce Rogers <brogers@suse.com>
---
 target/arm/internals.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/target/arm/internals.h b/target/arm/internals.h
index 5460678756d3c4e5f34abe5f6411..73698587d6b8eeffd6ccd1515e7a 100644
--- a/target/arm/internals.h
+++ b/target/arm/internals.h
@@ -1312,6 +1312,15 @@ void arm_log_exception(int idx);
 #define LOG2_TAG_GRANULE 4
 #define TAG_GRANULE      (1 << LOG2_TAG_GRANULE)
 
+/*
+ * SVE predicates are 1/8 the size of SVE vectors, and cannot use
+ * the same simd_desc() encoding due to restrictions on size.
+ * Use these instead.
+ */
+FIELD(PREDDESC, OPRSZ, 0, 6)
+FIELD(PREDDESC, ESZ, 6, 2)
+FIELD(PREDDESC, DATA, 8, 24)
+
 /*
  * The SVE simd_data field, for memory ops, contains either
  * rd (5 bits) or a shift count (2 bits).

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File target-arm-Introduce-PREDDESC-field-defi.patch of Package qemu.20747

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