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| author | Anders O Nilsson <anders.o.nilsson@stericsson.com> | 2012-10-10 15:26:32 +0200 |
|---|---|---|
| committer | Patrik Ryd <patrik.ryd@stericsson.com> | 2013-06-14 15:25:48 +0200 |
| commit | 20111d635e9210bdd105219eceb263607ec4d5c5 (patch) | |
| tree | ee87e45903cae6cbc95e5657736450606690f279 /vm/compiler/codegen/arm/Thumb2 | |
| parent | 6529809bd4448a76622a08cf63829cab73d91b9a (diff) | |
| download | android_dalvik-20111d635e9210bdd105219eceb263607ec4d5c5.tar.gz android_dalvik-20111d635e9210bdd105219eceb263607ec4d5c5.tar.bz2 android_dalvik-20111d635e9210bdd105219eceb263607ec4d5c5.zip | |
JIT: Use rsb and shift in easy multiply.
For easy multiplication using reverse subtract (when
lit is 2^n-1) use the barrel shifter for rsb.
This improves arithmetic performance for code executing
in Dalvik. E.g String.hashCode.
Change-Id: Ifb086dcec344b30fd3e392ac21d508b43e820cdc
Signed-off-by: Patrik Ryd <patrik.ryd@stericsson.com>
Diffstat (limited to 'vm/compiler/codegen/arm/Thumb2')
| -rw-r--r-- | vm/compiler/codegen/arm/Thumb2/Gen.cpp | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/vm/compiler/codegen/arm/Thumb2/Gen.cpp b/vm/compiler/codegen/arm/Thumb2/Gen.cpp index ea6454779..950da906c 100644 --- a/vm/compiler/codegen/arm/Thumb2/Gen.cpp +++ b/vm/compiler/codegen/arm/Thumb2/Gen.cpp @@ -453,3 +453,10 @@ static void genMultiplyByTwoBitMultiplier(CompilationUnit *cUnit, opRegRegImm(cUnit, kOpLsl, rlResult.lowReg, rlResult.lowReg, firstBit); } } + +static void genMultiplyByShiftAndReverseSubtract(CompilationUnit *cUnit, + RegLocation rlSrc, RegLocation rlResult, int lit) +{ + newLIR4(cUnit, kThumb2RsbRRR, rlResult.lowReg, rlSrc.lowReg, rlSrc.lowReg, + encodeShift(kArmLsl, lit)); +} |