diff options
Diffstat (limited to 'vm/compiler/template/armv5te/TEMPLATE_CMPL_FLOAT.S')
| -rw-r--r-- | vm/compiler/template/armv5te/TEMPLATE_CMPL_FLOAT.S | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/vm/compiler/template/armv5te/TEMPLATE_CMPL_FLOAT.S b/vm/compiler/template/armv5te/TEMPLATE_CMPL_FLOAT.S new file mode 100644 index 0000000..eb1c7e1 --- /dev/null +++ b/vm/compiler/template/armv5te/TEMPLATE_CMPL_FLOAT.S @@ -0,0 +1,54 @@ +%default { "naninst":"mvn r0, #0" } + /* + * For the JIT: incoming arguments in r0-r1, r2-r3 + * result in r0 + * + * Compare two floating-point values. Puts 0, 1, or -1 into the + * destination register based on the results of the comparison. + * + * Provide a "naninst" instruction that puts 1 or -1 into r1 depending + * on what value we'd like to return when one of the operands is NaN. + * + * The operation we're implementing is: + * if (x == y) + * return 0; + * else if (x < y) + * return -1; + * else if (x > y) + * return 1; + * else + * return {-1,1}; // one or both operands was NaN + * + * The straightforward implementation requires 3 calls to functions + * that return a result in r0. We can do it with two calls if our + * EABI library supports __aeabi_cfcmple (only one if we want to check + * for NaN directly): + * check x <= y + * if <, return -1 + * if ==, return 0 + * check y <= x + * if <, return 1 + * return {-1,1} + * + * for: cmpl-float, cmpg-float + */ + /* op vAA, vBB, vCC */ + mov r9, r0 @ Save copies - we may need to redo + mov r10, r1 + mov r11, lr @ save return address + LDR_PC_LR ".L__aeabi_cfcmple" @ cmp <=: C clear if <, Z set if eq + bhi .L${opcode}_gt_or_nan @ C set and Z clear, disambiguate + mvncc r0, #0 @ (less than) r0<- -1 + moveq r0, #0 @ (equal) r0<- 0, trumps less than + bx r11 + @ Test for NaN with a second comparison. EABI forbids testing bit + @ patterns, and we can't represent 0x7fc00000 in immediate form, so + @ make the library call. +.L${opcode}_gt_or_nan: + mov r0, r10 @ restore in reverse order + mov r1, r9 + LDR_PC_LR ".L__aeabi_cfcmple" @ r0<- Z set if eq, C clear if < + movcc r0, #1 @ (greater than) r1<- 1 + bxcc r11 + $naninst @ r1<- 1 or -1 for NaN + bx r11 |