diff options
Diffstat (limited to 'js/src/jit-test/tests/sunspider/check-bitops-3bit-bits-in-byte.js')
-rw-r--r-- | js/src/jit-test/tests/sunspider/check-bitops-3bit-bits-in-byte.js | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/sunspider/check-bitops-3bit-bits-in-byte.js b/js/src/jit-test/tests/sunspider/check-bitops-3bit-bits-in-byte.js new file mode 100644 index 000000000..39bf060d0 --- /dev/null +++ b/js/src/jit-test/tests/sunspider/check-bitops-3bit-bits-in-byte.js @@ -0,0 +1,35 @@ +// Copyright (c) 2004 by Arthur Langereis (arthur_ext at domain xfinitegames, tld com + +// 1 op = 6 ANDs, 3 SHRs, 3 SHLs, 4 assigns, 2 ADDs +// O(1) +function fast3bitlookup(b) { +var c, bi3b = 0xE994; // 0b1110 1001 1001 0100; // 3 2 2 1 2 1 1 0 +c = 3 & (bi3b >> ((b << 1) & 14)); +c += 3 & (bi3b >> ((b >> 2) & 14)); +c += 3 & (bi3b >> ((b >> 5) & 6)); +return c; + +/* +lir4,0xE994; 9 instructions, no memory access, minimal register dependence, 6 shifts, 2 adds, 1 inline assign +rlwinmr5,r3,1,28,30 +rlwinmr6,r3,30,28,30 +rlwinmr7,r3,27,29,30 +rlwnmr8,r4,r5,30,31 +rlwnmr9,r4,r6,30,31 +rlwnmr10,r4,r7,30,31 +addr3,r8,r9 +addr3,r3,r10 +*/ +} + +var ret = 0; +function TimeFunc(func) { + var x, y, t; + for(var x=0; x<500; x++) + for(var y=0; y<256; y++) { + ret += func(y); + } +} + +TimeFunc(fast3bitlookup); +assertEq(ret, 512000) |