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/arm64/quick_entrypoints_arm64.S b/runtime/arch/arm64/quick_entrypoints_arm64.S
index 10ee63f..e9ad1f4 100644
--- a/runtime/arch/arm64/quick_entrypoints_arm64.S
+++ b/runtime/arch/arm64/quick_entrypoints_arm64.S
@@ -2214,3 +2214,59 @@
asr x0, x0, #1
ret
END art_quick_indexof
+
+ /*
+ * 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 W0);
+ * - `reg` is used to return the result of this function (instead of W0);
+ * - W0 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
+ str xLR, [sp, #-16]! // Save return address and add padding (16B align stack).
+ .cfi_adjust_cfa_offset 16
+ .cfi_rel_offset x30, 0
+ mov w0, \reg // Pass arg1 - obj from `reg`
+ bl artReadBarrierMark // artReadBarrierMark(obj)
+ mov \reg, w0 // Return result into `reg`
+ ldr xLR, [sp], #16 // Restore return address and remove padding.
+ .cfi_restore x30
+ .cfi_adjust_cfa_offset -16
+ ret
+END \name
+.endm
+
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg01, w1
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg02, w2
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg03, w3
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg04, w4
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg05, w5
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg06, w6
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg07, w7
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg08, w8
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg09, w9
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg10, w10
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg11, w11
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg12, w12
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg13, w13
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg14, w14
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg15, w15
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg16, w16
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg17, w17
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg18, w18
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg19, w19
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg20, w20
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg21, w21
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg22, w22
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg23, w23
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg24, w24
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg25, w25
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg26, w26
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg27, w27
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg28, w28
+READ_BARRIER_MARK_REG art_quick_read_barrier_mark_reg29, w29