diff mbox series

[v2,07/17] qemu/bitops.h: Limit rotate amounts

Message ID 20230417135821.609964-8-lawrence.hunter@codethink.co.uk (mailing list archive)
State New, archived
Headers show
Series Add RISC-V vector cryptographic instruction set support | expand

Commit Message

Lawrence Hunter April 17, 2023, 1:58 p.m. UTC 
From: Dickon Hood <dickon.hood@codethink.co.uk>

Rotates have been fixed up to only allow for reasonable rotate amounts
(ie, no rotates >7 on an 8b value etc.)  This fixes a problem with riscv
vector rotate instructions.

Signed-off-by: Dickon Hood <dickon.hood@codethink.co.uk>
---
 include/qemu/bitops.h | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

Comments

Richard Henderson April 18, 2023, 8:19 a.m. UTC | #1 
On 4/17/23 15:58, Lawrence Hunter wrote:
> From: Dickon Hood<dickon.hood@codethink.co.uk>
> 
> Rotates have been fixed up to only allow for reasonable rotate amounts
> (ie, no rotates >7 on an 8b value etc.)  This fixes a problem with riscv
> vector rotate instructions.
> 
> Signed-off-by: Dickon Hood<dickon.hood@codethink.co.uk>
> ---
>   include/qemu/bitops.h | 24 ++++++++++++++++--------
>   1 file changed, 16 insertions(+), 8 deletions(-)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~
diff mbox series

Patch

diff --git a/include/qemu/bitops.h b/include/qemu/bitops.h
index 03213ce952c..c443995b3ba 100644
--- a/include/qemu/bitops.h
+++ b/include/qemu/bitops.h
@@ -218,7 +218,8 @@  static inline unsigned long find_first_zero_bit(const unsigned long *addr,
  */
 static inline uint8_t rol8(uint8_t word, unsigned int shift)
 {
-    return (word << shift) | (word >> ((8 - shift) & 7));
+    shift &= 7;
+    return (word << shift) | (word >> (8 - shift));
 }
 
 /**
@@ -228,7 +229,8 @@  static inline uint8_t rol8(uint8_t word, unsigned int shift)
  */
 static inline uint8_t ror8(uint8_t word, unsigned int shift)
 {
-    return (word >> shift) | (word << ((8 - shift) & 7));
+    shift &= 7;
+    return (word >> shift) | (word << (8 - shift));
 }
 
 /**
@@ -238,7 +240,8 @@  static inline uint8_t ror8(uint8_t word, unsigned int shift)
  */
 static inline uint16_t rol16(uint16_t word, unsigned int shift)
 {
-    return (word << shift) | (word >> ((16 - shift) & 15));
+    shift &= 15;
+    return (word << shift) | (word >> (16 - shift));
 }
 
 /**
@@ -248,7 +251,8 @@  static inline uint16_t rol16(uint16_t word, unsigned int shift)
  */
 static inline uint16_t ror16(uint16_t word, unsigned int shift)
 {
-    return (word >> shift) | (word << ((16 - shift) & 15));
+    shift &= 15;
+    return (word >> shift) | (word << (16 - shift));
 }
 
 /**
@@ -258,7 +262,8 @@  static inline uint16_t ror16(uint16_t word, unsigned int shift)
  */
 static inline uint32_t rol32(uint32_t word, unsigned int shift)
 {
-    return (word << shift) | (word >> ((32 - shift) & 31));
+    shift &= 31;
+    return (word << shift) | (word >> (32 - shift));
 }
 
 /**
@@ -268,7 +273,8 @@  static inline uint32_t rol32(uint32_t word, unsigned int shift)
  */
 static inline uint32_t ror32(uint32_t word, unsigned int shift)
 {
-    return (word >> shift) | (word << ((32 - shift) & 31));
+    shift &= 31;
+    return (word >> shift) | (word << (32 - shift));
 }
 
 /**
@@ -278,7 +284,8 @@  static inline uint32_t ror32(uint32_t word, unsigned int shift)
  */
 static inline uint64_t rol64(uint64_t word, unsigned int shift)
 {
-    return (word << shift) | (word >> ((64 - shift) & 63));
+    shift &= 63;
+    return (word << shift) | (word >> (64 - shift));
 }
 
 /**
@@ -288,7 +295,8 @@  static inline uint64_t rol64(uint64_t word, unsigned int shift)
  */
 static inline uint64_t ror64(uint64_t word, unsigned int shift)
 {
-    return (word >> shift) | (word << ((64 - shift) & 63));
+    shift &= 63;
+    return (word >> shift) | (word << (64 - shift));
 }
 
 /**