target/arm: Reorg VHE redirection

[PATCH v2 21/36] target/arm: Improve asserts in define_one_arm_cp_reg

Posted by Richard Henderson 1 week, 5 days ago

Reject ARM_CP_64BIT with ARM_CP_STATE_BOTH, because encoding
constrains prevent it from working.  Remove some extra parens;
distribute ! across && to simplify.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/helper.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/target/arm/helper.c b/target/arm/helper.c
index ec78c8f08f..8a805695e7 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -7706,12 +7706,17 @@ void define_one_arm_cp_reg(ARMCPU *cpu, const ARMCPRegInfo *r)
     int opc2min = (r->opc2 == CP_ANY) ? 0 : r->opc2;
     int opc2max = (r->opc2 == CP_ANY) ? 7 : r->opc2;
 
-    /* 64 bit registers have only CRm and Opc1 fields */
-    assert(!((r->type & ARM_CP_64BIT) && (r->opc2 || r->crn)));
+    /*
+     * AArch64 regs are all 64 bit so ARM_CP_64BIT is meaningless.
+     * Moreover, the encoding test just following in general prevents
+     * shared encoding so ARM_CP_STATE_BOTH won't work either.
+     */
+    assert(r->state == ARM_CP_STATE_AA32 || !(r->type & ARM_CP_64BIT));
+    /* AArch32 64-bit registers have only CRm and Opc1 fields. */
+    assert(!(r->type & ARM_CP_64BIT) || !(r->opc2 || r->crn));
     /* op0 only exists in the AArch64 encodings */
-    assert((r->state != ARM_CP_STATE_AA32) || (r->opc0 == 0));
-    /* AArch64 regs are all 64 bit so ARM_CP_64BIT is meaningless */
-    assert((r->state != ARM_CP_STATE_AA64) || !(r->type & ARM_CP_64BIT));
+    assert(r->state != ARM_CP_STATE_AA32 || r->opc0 == 0);
+
     /*
      * This API is only for Arm's system coprocessors (14 and 15) or
      * (M-profile or v7A-and-earlier only) for implementation defined
-- 
2.43.0

Re: [PATCH v2 21/36] target/arm: Improve asserts in define_one_arm_cp_reg

Posted by Philippe Mathieu-Daudé 3 days, 5 hours ago

On 16/9/25 16:22, Richard Henderson wrote:
> Reject ARM_CP_64BIT with ARM_CP_STATE_BOTH, because encoding
> constrains prevent it from working.  Remove some extra parens;
> distribute ! across && to simplify.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   target/arm/helper.c | 15 ++++++++++-----
>   1 file changed, 10 insertions(+), 5 deletions(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Tested-by: Philippe Mathieu-Daudé <philmd@linaro.org>