Turn select C, (X+Y), (X-Y) --> (X+(select C, Y, (-Y))). This occurs in
the 'sim' program and probably elsewhere. In sim, it comes up for cases
like this:
#define round(x) ((x)>0.0 ? (x)+0.5 : (x)-0.5)
double G;
void T(double X) { G = round(X); }
(it uses the round macro a lot). This changes the LLVM code from:
%tmp.1 = setgt double %X, 0.000000e+00 ; <bool> [#uses=1]
%tmp.4 = add double %X, 5.000000e-01 ; <double> [#uses=1]
%tmp.6 = sub double %X, 5.000000e-01 ; <double> [#uses=1]
%mem_tmp.0 = select bool %tmp.1, double %tmp.4, double %tmp.6
store double %mem_tmp.0, double* %G
to:
%tmp.1 = setgt double %X, 0.000000e+00 ; <bool> [#uses=1]
%mem_tmp.0.p = select bool %tmp.1, double 5.000000e-01, double -5.000000e-01
%mem_tmp.0 = add double %mem_tmp.0.p, %X
store double %mem_tmp.0, double* %G
ret void
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19537 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed