Introduce more compact ReadBarrierMark slow-paths.
Replace entry point ReadBarrierMark with 32
ReadBarrierMarkRegX entry points, using register
number X as input and output (instead of the standard
runtime calling convention) to save two moves in Baker's
read barrier mark slow-path code.
Test: ART host and target (ARM, ARM64) tests.
Bug: 29506760
Bug: 12687968
Change-Id: I73cfb82831cf040b8b018e984163c865cc44ed87
diff --git a/runtime/arch/arm/quick_entrypoints_arm.S b/runtime/arch/arm/quick_entrypoints_arm.S
index d940164..82d64b9 100644
--- a/runtime/arch/arm/quick_entrypoints_arm.S
+++ b/runtime/arch/arm/quick_entrypoints_arm.S
@@ -1743,3 +1743,43 @@
.cfi_adjust_cfa_offset -4
pop {pc}
END art_quick_l2f
+
+ /*
+ * Create a function `name` calling the ReadBarrier::Mark routine,
+ * getting its argument and returning its result through register
+ * `reg`, thus following a non-standard runtime calling convention:
+ * - `reg` is used to pass the (sole) argument of this function
+ * (instead of R0);
+ * - `reg` is used to return the result of this function (instead of R0);
+ * - R0 is treated like a normal (non-argument) caller-save register;
+ * - everything else is the same as in the standard runtime calling
+ * convention (e.g. same callee-save registers).
+ */
+.macro READ_BARRIER_MARK_REG name, reg
+ENTRY \name
+ push {lr} @ save return address
+ .cfi_adjust_cfa_offset 4
+ .cfi_rel_offset lr, 0
+ sub sp, #4 @ push padding (native calling convention 8-byte alignment)
+ .cfi_adjust_cfa_offset 4
+ mov r0, \reg @ pass arg1 - obj from `reg`
+ bl artReadBarrierMark @ artReadBarrierMark(obj)
+ mov \reg, r0 @ return result into `reg`
+ add sp, #4 @ pop padding
+ .cfi_adjust_cfa_offset -4
+ pop {pc} @ return
+END \name
+.endm
+
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg01, r1
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg02, r2
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg03, r3
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg04, r4
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg05, r5
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg06, r6
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg07, r7
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg08, r8
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg09, r9
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg10, r10
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg11, r11
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg12, r12