The Vector<T> version of this benchmark (BilinearInterpol_Vector) has a number of weaknesses:
First, although the temporary array doubleTemp is allocated with a constant length:
STMT00015 (IL 0x0AD... ???)
[000113] -ACXG------- * ASG ref
[000112] D------N---- +--* LCL_VAR ref V24 loc15
[000111] --CXG------- \--* CALL help ref HELPER.CORINFO_HELP_NEWARR_1_VC
[000110] ------------ arg0 +--* CNS_INT(h) long 0x7ffafe875b00 class
[000109] ------------ arg1 \--* CNS_INT long 4 vector element count
The loop cloning code is unable to determine V24.length:
Considering condition 0: (4 LE V24.Length), could not be evaluated
So it decides to clone the loop, AFAICT so that it can eliminate the range check on doubleTemp, but then it eliminates it from both clones so we have identical loops. Furthermore, although the exact loop count is available, none of the 4 original loops, nor their identical clones, are unrolled.
category:cq
theme:loop-opt
skill-level:expert
cost:large
The
Vector<T>version of this benchmark (BilinearInterpol_Vector) has a number of weaknesses:First, although the temporary array
doubleTempis allocated with a constant length:The loop cloning code is unable to determine
V24.length:So it decides to clone the loop, AFAICT so that it can eliminate the range check on
doubleTemp, but then it eliminates it from both clones so we have identical loops. Furthermore, although the exact loop count is available, none of the 4 original loops, nor their identical clones, are unrolled.category:cq
theme:loop-opt
skill-level:expert
cost:large