search for: call_change_rounding_mod

an interesting problem occurs if you do interval arithmetic. void foo() { float XL, XU, Y, Z; .... call_change_rounding_mode(lower); XL = Y + Z; // lower bound call_change_rounding_mode(upper); XU = Y + Z; } Two issues here: 1) will the compiler mistakenly treat Y+Z as a common subexpression. 2) might it move the call_change_rounding_mode after the assignment to XU since it seens no dependency. This is actually to m...

...ps.com> > To: LLVMdev at cs.uiuc.edu > Sent: Wednesday, April 17, 2013 8:32:23 PM > Subject: [LLVMdev] optimization in presence of floating point > > an interesting problem occurs if you do interval arithmetic. > > void foo() { > float XL, XU, Y, Z; > > .... > call_change_rounding_mode(lower); > XL = Y + Z; // lower bound > call_change_rounding_mode(upper); > XU = Y + Z; > > } > > Two issues here: > 1) will the compiler mistakenly treat Y+Z as a common subexpression. > 2) might it move the call_change_rounding_mode after the assignment > to > X...

...c.edu >> Sent: Wednesday, April 17, 2013 8:32:23 PM >> Subject: [LLVMdev] optimization in presence of floating point >> >> an interesting problem occurs if you do interval arithmetic. >> >> void foo() { >> float XL, XU, Y, Z; >> >> .... >> call_change_rounding_mode(lower); >> XL = Y + Z; // lower bound >> call_change_rounding_mode(upper); >> XU = Y + Z; >> >> } >> >> Two issues here: >> 1) will the compiler mistakenly treat Y+Z as a common subexpression. >> 2) might it move the call_change_rounding_mode a...