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| author | Jan Kotas <jkotas@microsoft.com> | 2015-11-20 07:16:03 -0800 |
|---|---|---|
| committer | Jan Kotas <jkotas@microsoft.com> | 2015-11-20 07:16:03 -0800 |
| commit | 4684dfd670b1ebc924e8d3739739abb56ab2408e (patch) | |
| tree | 141f0dcb4c5cea5b525300a9b56f11a44882f358 /src/vm/amd64 | |
| parent | 227abcd8ca79fa0b0b5d4238e11c99a419f3f510 (diff) | |
| parent | 3c9506f2e121ebc3781ec53c17fa585629993ee8 (diff) | |
| download | coreclr-4684dfd670b1ebc924e8d3739739abb56ab2408e.tar.gz coreclr-4684dfd670b1ebc924e8d3739739abb56ab2408e.tar.bz2 coreclr-4684dfd670b1ebc924e8d3739739abb56ab2408e.zip | |
Merge pull request #2114 from sergiy-k/byrefrax
Do not preserve volatile registers in JIT_ByRefWriteBarrier
Diffstat (limited to 'src/vm/amd64')
| -rw-r--r-- | src/vm/amd64/jithelpers_fast.S | 21 |
1 files changed, 9 insertions, 12 deletions
diff --git a/src/vm/amd64/jithelpers_fast.S b/src/vm/amd64/jithelpers_fast.S index a981254806..1dfc3ef164 100644 --- a/src/vm/amd64/jithelpers_fast.S +++ b/src/vm/amd64/jithelpers_fast.S @@ -122,11 +122,18 @@ LEAF_END_MARKED JIT_CheckedWriteBarrier, _TEXT // Entry: // RDI - address of ref-field (assigned to) // RSI - address of the data (source) -// RCX can be trashed +// +// Note: RyuJIT assumes that all volatile registers can be trashed by +// the CORINFO_HELP_ASSIGN_BYREF helper (i.e. JIT_ByRefWriteBarrier). +// The precise set is defined by RBM_CALLEE_TRASH. +// +// RCX is trashed +// RAX is trashed +// R10 is trashed on Debug build +// R11 is trashed on Debug build // Exit: // RDI, RSI are incremented by SIZEOF(LPVOID) LEAF_ENTRY JIT_ByRefWriteBarrier, _TEXT - push rax mov rcx, [rsi] // If !WRITE_BARRIER_CHECK do the write first, otherwise we might have to do some ShadowGC stuff @@ -147,11 +154,6 @@ LEAF_ENTRY JIT_ByRefWriteBarrier, _TEXT jnb NotInHeap_ByRefWriteBarrier #ifdef WRITE_BARRIER_CHECK - // we can only trash rcx in this function so in _DEBUG we need to save - // some scratch registers. - push r10 - push r11 - // **ALSO update the shadow GC heap if that is enabled** // Do not perform the work if g_GCShadow is 0 PREPARE_EXTERNAL_VAR g_GCShadow, rax @@ -199,8 +201,6 @@ LEAF_ENTRY JIT_ByRefWriteBarrier, _TEXT // Additionally we know for sure that we are inside the heap and therefore don't // need to replicate the above checks. DoneShadow_ByRefWriteBarrier: - pop r11 - pop r10 #endif // See if we can just quick out @@ -222,8 +222,6 @@ LEAF_ENTRY JIT_ByRefWriteBarrier, _TEXT PREPARE_EXTERNAL_VAR g_card_table, rax add rcx, [rax] - pop rax - // Check if this card is dirty cmp byte ptr [rcx], 0FFh jne UpdateCardTable_ByRefWriteBarrier @@ -246,6 +244,5 @@ LEAF_ENTRY JIT_ByRefWriteBarrier, _TEXT // Increment the pointers before leaving add rdi, 8h add rsi, 8h - pop rax ret LEAF_END JIT_ByRefWriteBarrier, _TEXT |