diff options
Diffstat (limited to 'runtime/arm/i64_shr.S')
| -rw-r--r-- | runtime/arm/i64_shr.S | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/runtime/arm/i64_shr.S b/runtime/arm/i64_shr.S index a5418f4a..43325092 100644 --- a/runtime/arm/i64_shr.S +++ b/runtime/arm/i64_shr.S @@ -17,7 +17,7 @@ @ * Neither the name of the <organization> nor the @ names of its contributors may be used to endorse or promote products @ derived from this software without specific prior written permission. -@ +@ @ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS @ "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT @ LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR @@ -36,20 +36,20 @@ #include "sysdeps.h" -@@@ Shift right unsigned +@@@ Shift right unsigned @ Note on ARM shifts: the shift amount is taken modulo 256. @ If shift amount mod 256 >= 32, the shift produces 0. @ Algorithm: @ RL = (XL >> N) | (XH << (32-N) | (XH >> (N-32)) -@ RH = XH >> N +@ RH = XH >> N @ If N = 0: @ RL = XL | 0 | 0 @ RH = XH @ If 1 <= N <= 31: 1 <= 32-N <= 31 and 255 <= N-32 mod 256 <= 255 @ RL = (XL >> N) | (XH >> (32-N) | 0 -@ RH = XH >> N +@ RH = XH >> N @ If N = 32: @ RL = 0 | XH | 0 @ RH = 0 @@ -60,12 +60,12 @@ FUNCTION(__i64_shr) AND r2, r2, #63 @ normalize amount to 0...63 RSB r3, r2, #32 @ r3 = 32 - amount - LSR r0, r0, r2 - LSL r3, r1, r3 - ORR r0, r0, r3 - SUB r3, r2, #32 @ r3 = amount - 32 - LSR r3, r1, r3 - ORR r0, r0, r3 - LSR r1, r1, r2 + LSR Reg0LO, Reg0LO, r2 + LSL r3, Reg0HI, r3 + ORR Reg0LO, Reg0LO, r3 + SUB r3, r2, #32 @ r3 = amount - 32 + LSR r3, Reg0HI, r3 + ORR Reg0LO, Reg0LO, r3 + LSR Reg0HI, Reg0HI, r2 bx lr ENDFUNCTION(__i64_shr) |