diff options
| -rw-r--r-- | lib/Target/X86/README.txt | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/lib/Target/X86/README.txt b/lib/Target/X86/README.txt index e139f03310..7bff7fea57 100644 --- a/lib/Target/X86/README.txt +++ b/lib/Target/X86/README.txt @@ -161,6 +161,14 @@ http://gcc.gnu.org/ml/gcc-patches/2004-08/msg02011.html Combine: a = sin(x), b = cos(x) into a,b = sincos(x). +Expand these to calls of sin/cos and stores: + double sincos(double x, double *sin, double *cos); + float sincosf(float x, float *sin, float *cos); + long double sincosl(long double x, long double *sin, long double *cos); + +Doing so could allow SROA of the destination pointers. See also: +http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17687 + //===---------------------------------------------------------------------===// The instruction selector sometimes misses folding a load into a compare. The @@ -386,3 +394,16 @@ LBB_X_2: The x86 backend currently supports dynamic-no-pic. Need to add asm printer support for static and PIC. + +//===---------------------------------------------------------------------===// + +We should generate bts/btr/etc instructions on targets where they are cheap or +when codesize is important. e.g., for: + +void setbit(int *target, int bit) { + *target |= (1 << bit); +} +void clearbit(int *target, int bit) { + *target &= ~(1 << bit); +} + |