Re-enable ARM32 JIT compiler
Andrew Hughes
gnu.andrew at redhat.com
Mon Mar 17 12:31:38 UTC 2014
----- Original Message -----
> The bug was actually in the asm interpreter, but it broke the JIT.
> Here:
>
> @@ -870,7 +873,7 @@
>
> SLOW_ENTRY
> empty_entry:
> - ldrh r3, [r0, #42]
> + ldrh r3, [r0, #METHOD_SIZEOFPARAMETERS]
>
> This code adjusts the stack pointer after an empty method is called.
> 42 is wrong: it should be the field offset of
> methodOopDesc::_size_of_parameters. While I was at it I found a
> couple more literals and changed them to symbolic names.
>
> I also took the opportunity to fix a few bugs. I made the tracing
> code more robust, and commented out some debugging calls that slow
> down the interpreter. I also fixed a bug in the helper routines that
> were using a static local to hold the address of the card table base:
> this is pointlessly slower than using a non-static local.
>
> Andrew.
>
>
> # HG changeset patch
> # User aph
> # Date 1395056000 0
> # Node ID 2de808a5820a68b390d05ab56934dbca8dbd9dcf
> # Parent 720c95f2266397040d878e255015b638d63c8c56
> Re-enable ARM32 JIT compiler.
>
> Replace literal offsets for METHOD_SIZEOFPARAMETERS and
> ISTATE_NEXT_FRAME with correct symbolic names.
> Fix trace code not to dereference null pointers.
> Correct Helper_aputfield and helper_aastore not to use static
> _byte_map_base.
> Comment-out calls to TRACE.
> Make sure that ISTATE_METHOD and ISTATE_SELF_LINK are set even when
> JITting fails.
>
> diff -r 720c95f22663 -r 2de808a5820a src/cpu/zero/vm/asm_helper.cpp
> --- a/src/cpu/zero/vm/asm_helper.cpp Thu Feb 20 15:02:19 2014 +0000
> +++ b/src/cpu/zero/vm/asm_helper.cpp Mon Mar 17 11:33:20 2014 +0000
> @@ -378,22 +378,16 @@
> goto handle_exception;
> }
> }
> - oop* elem_loc = (oop*)(((address) arrayref->base(T_OBJECT)) + index *
> sizeof(oop));
> - // *(oop*)(((address) arrayref->base(T_OBJECT)) + index * sizeof(oop))
> = value;
> - *elem_loc = value;
> - // Mark the card
> - BarrierSet* bs = Universe::heap()->barrier_set();
> - static volatile jbyte* _byte_map_base = (volatile
> jbyte*)(((CardTableModRefBS*)bs)->byte_map_base);
> - OrderAccess::release_store(&_byte_map_base[(uintptr_t)elem_loc >>
> CardTableModRefBS::card_shift], 0);
> + ((objArrayOopDesc *) arrayref)->obj_at_put(index, value);
> }
> handle_exception:
> return istate->thread()->pending_exception();
> }
>
> -extern "C" void Helper_aputfield(oop obj)
> +extern "C" void Helper_aputfield(oop obj, oop val, int offset)
> {
> BarrierSet* bs = Universe::heap()->barrier_set();
> - static volatile jbyte* _byte_map_base = (volatile
> jbyte*)(((CardTableModRefBS*)bs)->byte_map_base);
> + jbyte* _byte_map_base = (((CardTableModRefBS*)bs)->byte_map_base);
> OrderAccess::release_store(&_byte_map_base[(uintptr_t)obj >>
> CardTableModRefBS::card_shift], 0);
> }
>
> diff -r 720c95f22663 -r 2de808a5820a src/cpu/zero/vm/cppInterpreter_arm.S
> --- a/src/cpu/zero/vm/cppInterpreter_arm.S Thu Feb 20 15:02:19 2014 +0000
> +++ b/src/cpu/zero/vm/cppInterpreter_arm.S Mon Mar 17 11:33:20 2014 +0000
> @@ -526,10 +526,13 @@
> mrs r4, cpsr
> mov r0, jpc
> ldr r1, [thread, #THREAD_TOP_ZERO_FRAME]
> + cmp r1, #0
> sub r1, r1, #ISTATE_NEXT_FRAME
> + beq 0f
> + DECACHE_JPC
> ldr r2, =my_trace
> blx r2
> - msr cpsr, r4
> +0: msr cpsr, r4
> ldmfd sp!, {r0, r1, r2, r3, r4, ip, lr}
> .endm
>
> @@ -551,7 +554,7 @@
> .elseif dispatch_state == 4
> DISPATCH_4
> .endif
> - TRACE
> +@ TRACE
> moveq pc, ip
> ldrb r1, [jpc, lr]
> bic ip, ip, #7
> @@ -561,7 +564,7 @@
> .endm
>
> .macro DISPATCH_BYTECODE
> - TRACE
> +@ TRACE
> @ ldrb r1, [jpc, #2]
> ldr ip, [dispatch, r0, lsl #2]
> ldrb r2, [jpc, #1]
> @@ -870,7 +873,7 @@
>
> SLOW_ENTRY
> empty_entry:
> - ldrh r3, [r0, #42]
> + ldrh r3, [r0, #METHOD_SIZEOFPARAMETERS]
> ldr r1, [r2, #THREAD_JAVA_SP]
> add r1, r1, r3, lsl #2
> str r1, [r2, #THREAD_JAVA_SP]
> @@ -879,7 +882,7 @@
>
> FAST_ENTRY
> fast_empty_entry:
> - ldrh r3, [r0, #42]
> + ldrh r3, [r0, #METHOD_SIZEOFPARAMETERS]
> ldr r1, [thread, #THREAD_JAVA_SP]
> add r1, r1, r3, lsl #2
> str r1, [thread, #THREAD_JAVA_SP]
> @@ -1081,7 +1084,7 @@
>
> ldr r1, [thread, #THREAD_STACK_SIZE]
> ldr r3, [thread, #THREAD_STACK_BASE]
> - add r0, r9, #72
> + add r0, r9, #ISTATE_NEXT_FRAME
>
> rsb r3, r1, r3
> rsb r3, r3, arm_sp
> @@ -1104,7 +1107,7 @@
> str r5, [thread, #THREAD_LAST_JAVA_FP]
> ldr r5, [thread, #THREAD_JAVA_SP]
> str r5, [thread, #THREAD_LAST_JAVA_SP]
> - ldr r11, [r11, #-72 + ISTATE_METHOD]
> + ldr r11, [r11, #-ISTATE_NEXT_FRAME + ISTATE_METHOD]
> cmp r1, #0
> bne .fast_native_entry_exception
> ldr r5, [r11, #METHOD_SIGNATUREHANDLER]
> @@ -1127,7 +1130,7 @@
> ldr r11, [thread, #THREAD_TOP_ZERO_FRAME]
> ldr r1, [thread, #THREAD_PENDING_EXC]
> mov r3, #0
> - ldr r11, [r11, #-72 + ISTATE_METHOD]
> + ldr r11, [r11, #-ISTATE_NEXT_FRAME + ISTATE_METHOD]
> cmp r1, #0
> str r3, [thread, #THREAD_LAST_JAVA_SP]
> str r3, [thread, #THREAD_LAST_JAVA_FP]
> @@ -3353,12 +3356,12 @@
> str locals, [istate, #ISTATE_LOCALS]
> USEC cmp r3, lr
> str constpool, [istate, #ISTATE_CONSTANTS]
> + str tmp1, [istate, #ISTATE_METHOD]
> + str istate, [istate, #ISTATE_SELF_LINK]
> USEC bcs method_entry_freq_count_overflow
> DISPATCH_NEXT
> DISPATCH_NEXT
> DISPATCH_NEXT
> - str tmp1, [istate, #ISTATE_METHOD]
> - str istate, [istate, #ISTATE_SELF_LINK]
> @ mov lr, #0
> @ str lr, [istate, #ISTATE_PREV_LINK]
> @ str lr, [istate, #ISTATE_CALLEE]
>
Committed: http://icedtea.classpath.org/hg/icedtea7-forest/hotspot/rev/ee50fa9e8791
For some reason, this came through inline, so I had to manually copy and paste it
over. It also didn't apply cleanly, but the code seems identical, from manual
examination.
I didn't spot that the longer Changelog had got missed until later. Sorry. I'll
make sure to include it in the release notes instead, so it isn't lost.
Thanks for fixing this,
--
Andrew :)
Free Java Software Engineer
Red Hat, Inc. (http://www.redhat.com)
PGP Key: 248BDC07 (https://keys.indymedia.org/)
Fingerprint = EC5A 1F5E C0AD 1D15 8F1F 8F91 3B96 A578 248B DC07
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