diff options
| author | Dan Gohman <sunfish@google.com> | 2013-07-08 11:23:18 -0700 |
|---|---|---|
| committer | Dan Gohman <sunfish@google.com> | 2013-07-08 11:23:18 -0700 |
| commit | b090967580b4b1d03134b4dd11d849fd50f23951 (patch) | |
| tree | 041e5826045ab5482ac715b4e391cb30a09affea /tools/test-js-optimizer-asm-pre.js | |
| parent | 3117fa129fe2aef34a7c954bfe02c1eb0e5f8d29 (diff) | |
Xor optimizations.
Optimize x^-1 to ~x; this comes up because LLVM does not have a bitwise
negate operator. Optimize x&1^1 to !x; this comes up because of how LLVM
lowers C++ bool variables.
Also, add an optimization to simplifyExpressionsPre to eliminate |0 from
'~' expressions in more cases.
Diffstat (limited to 'tools/test-js-optimizer-asm-pre.js')
| -rw-r--r-- | tools/test-js-optimizer-asm-pre.js | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/tools/test-js-optimizer-asm-pre.js b/tools/test-js-optimizer-asm-pre.js index 7ca941fa..5c09043e 100644 --- a/tools/test-js-optimizer-asm-pre.js +++ b/tools/test-js-optimizer-asm-pre.js @@ -64,6 +64,12 @@ function b($this, $__n) { HEAP32[(($this + 4 | 0) & 16777215) >> 2] = $40; } HEAP8[($38 + $40 | 0) & 16777215] = 0; + // Eliminate the |0. + HEAP32[$4] = ((~(HEAP32[$5]|0))|0); + // Rewrite to ~. + HEAP32[$4] = HEAP32[$5]^-1; + // Rewrite to ~ and eliminate the |0. + HEAP32[$4] = ((HEAP32[$5]|0)^-1)|0; return; } function rett() { |