[#BOO-1112] Inefficient IL for unary negations (especially negative floating-point literals) - jira.codehaus.org

Boo

Created: 15/Jan/09 11:59 AM Updated: 15/Jan/09 02:06 PM Resolved: 15/Jan/09 02:06 PM

Return to search

Component/s:

Compiler

Affects Version/s:

0.8.2

Fix Version/s:

0.9

Time Tracking:

Not Specified

Description

« Hide

x as double = -1.0

Generates this:

ldc.r8 1.
ldc.i4 -1
conv.r8 
mul 
stloc.0

Instead of:

ldc.r8 -1.
stloc.0

x = -x (with x an int)

Generates this:

ldloc.0
ldc.i4 -1
mul 
stloc.0

Instead of:

ldc.i4.0
ldloc.0
sub.ovf
stloc.0

Or even (for unchecked blocks and any single/double):

ldloc.0
neg
stloc.0

Sort Order:

Cedric Vivier made changes - 15/Jan/09 12:00 PM

Field	Original Value	New Value
Description	x as double = -1.0 Generates this: {code} IL_0000: ldc.r8 1. IL_0009: ldc.i4 -1 IL_000e: conv.r8 IL_000f: mul IL_0010: conv.r4 IL_0011: stloc.0 {code} Instead of: {code} ldc.r8 -1. stloc.0 {code}	x as double = -1.0 Generates this: {code} ldc.r8 1. ldc.i4 -1 conv.r8 mul stloc.0 {code} Instead of: {code} ldc.r8 -1. stloc.0 {code}

Cedric Vivier made changes - 15/Jan/09 01:39 PM

Description	x as double = -1.0 Generates this: {code} ldc.r8 1. ldc.i4 -1 conv.r8 mul stloc.0 {code} Instead of: {code} ldc.r8 -1. stloc.0 {code}	x as double = -1.0 Generates this: {code} ldc.r8 1. ldc.i4 -1 conv.r8 mul stloc.0 {code} Instead of: {code} ldc.r8 -1. stloc.0 {code} x = -x (with x an int) Generates this: {code} ldloc.0 ldc.i4 -1 mul stloc.0 {code} Instead of: {code} ldc.i4.0 ldloc.0 sub.ovf stloc.0 {code} Or even (for unchecked blocks and any single/double): {code} ldloc.0 neg stloc.0 {code}
Summary	Very innefficient IL for negative floating-point literals	Inefficient IL for unary negations (especially negative floating-point literals)

[ Permalink | « Hide ]

Fixed in rev. 3103

Cedric Vivier made changes - 15/Jan/09 02:06 PM

Resolution		Fixed [ 1 ]
Status	Open [ 1 ]	Resolved [ 5 ]