String Compression for MIPS32 and MIPS64
Changes on intrinsics and Code Generation on MIPS32 and MIPS64 for
string compression feature.
Testing is done with STRING_COMPRESSION_ENABLED = true (in libcore),
mirror::kUseStringCompression = true and STRING_COMPRESSION_FEATURE set
to 1.
Test: booted MIPS32 and MIPS64 in QEMU
Test: mma test-art-target-run-test on CI20 (MIPS32R2)
Test: mma test-art-target-run-test in QEMU (MIPS64R6)
Change-Id: If50a6b6c0792bfa34d4fdff6bf2c7542211d2689
diff --git a/runtime/arch/mips/quick_entrypoints_mips.S b/runtime/arch/mips/quick_entrypoints_mips.S
index 10b690a..ec8ae85 100644
--- a/runtime/arch/mips/quick_entrypoints_mips.S
+++ b/runtime/arch/mips/quick_entrypoints_mips.S
@@ -2042,67 +2042,158 @@
/* $a0 holds address of "this" */
/* $a1 holds "ch" */
/* $a2 holds "fromIndex" */
- lw $t0, MIRROR_STRING_COUNT_OFFSET($a0) # this.length()
- slt $t1, $a2, $zero # if fromIndex < 0
-#if defined(_MIPS_ARCH_MIPS32R6) || defined(_MIPS_ARCH_MIPS64R6)
- seleqz $a2, $a2, $t1 # fromIndex = 0;
+#if (STRING_COMPRESSION_FEATURE)
+ lw $a3, MIRROR_STRING_COUNT_OFFSET($a0) # 'count' field of this
#else
- movn $a2, $zero, $t1 # fromIndex = 0;
+ lw $t0, MIRROR_STRING_COUNT_OFFSET($a0) # this.length()
#endif
- subu $t0, $t0, $a2 # this.length() - fromIndex
- blez $t0, 6f # if this.length()-fromIndex <= 0
- li $v0, -1 # return -1;
+ slt $t1, $a2, $zero # if fromIndex < 0
+#if defined(_MIPS_ARCH_MIPS32R6) || defined(_MIPS_ARCH_MIPS64R6)
+ seleqz $a2, $a2, $t1 # fromIndex = 0;
+#else
+ movn $a2, $zero, $t1 # fromIndex = 0;
+#endif
+#if (STRING_COMPRESSION_FEATURE)
+ srl $t0, $a3, 1 # $a3 holds count (with flag) and $t0 holds actual length
+#endif
+ subu $t0, $t0, $a2 # this.length() - fromIndex
+ blez $t0, 6f # if this.length()-fromIndex <= 0
+ li $v0, -1 # return -1;
- sll $v0, $a2, 1 # $a0 += $a2 * 2
- addu $a0, $a0, $v0 # " ditto "
- move $v0, $a2 # Set i to fromIndex.
+#if (STRING_COMPRESSION_FEATURE)
+ sll $a3, $a3, 31 # Extract compression flag.
+ beqz $a3, .Lstring_indexof_compressed
+ move $t2, $a0 # Save a copy in $t2 to later compute result (in branch delay slot).
+#endif
+ sll $v0, $a2, 1 # $a0 += $a2 * 2
+ addu $a0, $a0, $v0 # " ditto "
+ move $v0, $a2 # Set i to fromIndex.
1:
- lhu $t3, MIRROR_STRING_VALUE_OFFSET($a0) # if this.charAt(i) == ch
- beq $t3, $a1, 6f # return i;
- addu $a0, $a0, 2 # i++
- subu $t0, $t0, 1 # this.length() - i
- bnez $t0, 1b # while this.length() - i > 0
- addu $v0, $v0, 1 # i++
+ lhu $t3, MIRROR_STRING_VALUE_OFFSET($a0) # if this.charAt(i) == ch
+ beq $t3, $a1, 6f # return i;
+ addu $a0, $a0, 2 # i++
+ subu $t0, $t0, 1 # this.length() - i
+ bnez $t0, 1b # while this.length() - i > 0
+ addu $v0, $v0, 1 # i++
- li $v0, -1 # if this.length() - i <= 0
- # return -1;
+ li $v0, -1 # if this.length() - i <= 0
+ # return -1;
6:
- j $ra
- nop
+ j $ra
+ nop
+
+#if (STRING_COMPRESSION_FEATURE)
+.Lstring_indexof_compressed:
+ addu $a0, $a0, $a2 # $a0 += $a2
+
+.Lstring_indexof_compressed_loop:
+ lbu $t3, MIRROR_STRING_VALUE_OFFSET($a0)
+ beq $t3, $a1, .Lstring_indexof_compressed_matched
+ subu $t0, $t0, 1
+ bgtz $t0, .Lstring_indexof_compressed_loop
+ addu $a0, $a0, 1
+
+.Lstring_indexof_nomatch:
+ jalr $zero, $ra
+ li $v0, -1 # return -1;
+
+.Lstring_indexof_compressed_matched:
+ jalr $zero, $ra
+ subu $v0, $a0, $t2 # return (current - start);
+#endif
END art_quick_indexof
/* java.lang.String.compareTo(String anotherString) */
ENTRY_NO_GP art_quick_string_compareto
/* $a0 holds address of "this" */
/* $a1 holds address of "anotherString" */
- beq $a0, $a1, 9f # this and anotherString are the same object
- move $v0, $zero
+ beq $a0, $a1, .Lstring_compareto_length_diff # this and anotherString are the same object
+ move $a3, $a2 # trick to return 0 (it returns a2 - a3)
- lw $a2, MIRROR_STRING_COUNT_OFFSET($a0) # this.length()
- lw $a3, MIRROR_STRING_COUNT_OFFSET($a1) # anotherString.length()
- MINu $t2, $a2, $a3
-# $t2 now holds min(this.length(),anotherString.length())
+#if (STRING_COMPRESSION_FEATURE)
+ lw $t0, MIRROR_STRING_COUNT_OFFSET($a0) # 'count' field of this
+ lw $t1, MIRROR_STRING_COUNT_OFFSET($a1) # 'count' field of anotherString
+ sra $a2, $t0, 1 # this.length()
+ sra $a3, $t1, 1 # anotherString.length()
+#else
+ lw $a2, MIRROR_STRING_COUNT_OFFSET($a0) # this.length()
+ lw $a3, MIRROR_STRING_COUNT_OFFSET($a1) # anotherString.length()
+#endif
- beqz $t2, 9f # while min(this.length(),anotherString.length())-i != 0
- subu $v0, $a2, $a3 # if $t2==0 return
- # (this.length() - anotherString.length())
-1:
- lhu $t0, MIRROR_STRING_VALUE_OFFSET($a0) # while this.charAt(i) == anotherString.charAt(i)
- lhu $t1, MIRROR_STRING_VALUE_OFFSET($a1)
- bne $t0, $t1, 9f # if this.charAt(i) != anotherString.charAt(i)
- subu $v0, $t0, $t1 # return (this.charAt(i) - anotherString.charAt(i))
- addiu $a0, $a0, 2 # point at this.charAt(i++)
- subu $t2, $t2, 1 # new value of
- # min(this.length(),anotherString.length())-i
- bnez $t2, 1b
- addiu $a1, $a1, 2 # point at anotherString.charAt(i++)
- subu $v0, $a2, $a3
+ MINu $t2, $a2, $a3
+ # $t2 now holds min(this.length(),anotherString.length())
-9:
- j $ra
- nop
+ # while min(this.length(),anotherString.length())-i != 0
+ beqz $t2, .Lstring_compareto_length_diff # if $t2==0
+ nop # return (this.length() - anotherString.length())
+
+#if (STRING_COMPRESSION_FEATURE)
+ # Differ cases:
+ sll $t3, $t0, 31
+ beqz $t3, .Lstring_compareto_this_is_compressed
+ sll $t3, $t1, 31 # In branch delay slot.
+ beqz $t3, .Lstring_compareto_that_is_compressed
+ nop
+ b .Lstring_compareto_both_not_compressed
+ nop
+
+.Lstring_compareto_this_is_compressed:
+ beqz $t3, .Lstring_compareto_both_compressed
+ nop
+ /* If (this->IsCompressed() && that->IsCompressed() == false) */
+.Lstring_compareto_loop_comparison_this_compressed:
+ lbu $t0, MIRROR_STRING_VALUE_OFFSET($a0)
+ lhu $t1, MIRROR_STRING_VALUE_OFFSET($a1)
+ bne $t0, $t1, .Lstring_compareto_char_diff
+ addiu $a0, $a0, 1 # point at this.charAt(i++) - compressed
+ subu $t2, $t2, 1 # new value of min(this.length(),anotherString.length())-i
+ bnez $t2, .Lstring_compareto_loop_comparison_this_compressed
+ addiu $a1, $a1, 2 # point at anotherString.charAt(i++) - uncompressed
+ jalr $zero, $ra
+ subu $v0, $a2, $a3 # return (this.length() - anotherString.length())
+
+.Lstring_compareto_that_is_compressed:
+ lhu $t0, MIRROR_STRING_VALUE_OFFSET($a0)
+ lbu $t1, MIRROR_STRING_VALUE_OFFSET($a1)
+ bne $t0, $t1, .Lstring_compareto_char_diff
+ addiu $a0, $a0, 2 # point at this.charAt(i++) - uncompressed
+ subu $t2, $t2, 1 # new value of min(this.length(),anotherString.length())-i
+ bnez $t2, .Lstring_compareto_that_is_compressed
+ addiu $a1, $a1, 1 # point at anotherString.charAt(i++) - compressed
+ jalr $zero, $ra
+ subu $v0, $a2, $a3 # return (this.length() - anotherString.length())
+
+.Lstring_compareto_both_compressed:
+ lbu $t0, MIRROR_STRING_VALUE_OFFSET($a0)
+ lbu $t1, MIRROR_STRING_VALUE_OFFSET($a1)
+ bne $t0, $t1, .Lstring_compareto_char_diff
+ addiu $a0, $a0, 1 # point at this.charAt(i++) - compressed
+ subu $t2, $t2, 1 # new value of min(this.length(),anotherString.length())-i
+ bnez $t2, .Lstring_compareto_both_compressed
+ addiu $a1, $a1, 1 # point at anotherString.charAt(i++) - compressed
+ jalr $zero, $ra
+ subu $v0, $a2, $a3 # return (this.length() - anotherString.length())
+#endif
+
+.Lstring_compareto_both_not_compressed:
+ lhu $t0, MIRROR_STRING_VALUE_OFFSET($a0) # while this.charAt(i) == anotherString.charAt(i)
+ lhu $t1, MIRROR_STRING_VALUE_OFFSET($a1)
+ bne $t0, $t1, .Lstring_compareto_char_diff # if this.charAt(i) != anotherString.charAt(i)
+ # return (this.charAt(i) - anotherString.charAt(i))
+ addiu $a0, $a0, 2 # point at this.charAt(i++)
+ subu $t2, $t2, 1 # new value of min(this.length(),anotherString.length())-i
+ bnez $t2, .Lstring_compareto_both_not_compressed
+ addiu $a1, $a1, 2 # point at anotherString.charAt(i++)
+
+.Lstring_compareto_length_diff:
+ jalr $zero, $ra
+ subu $v0, $a2, $a3 # return (this.length() - anotherString.length())
+
+.Lstring_compareto_char_diff:
+ jalr $zero, $ra
+ subu $v0, $t0, $t1 # return (this.charAt(i) - anotherString.charAt(i))
END art_quick_string_compareto
.extern artInvokePolymorphic