The XL implementation of vec_round for vector double uses
"round-to-nearest, ties to even" just as the vector float
`version does. However clang and gcc use "round-to-nearest-away"
for vector double and "round-to-nearest, ties to even"
for vector float.
The XL behaviour is implemented under the __XL_COMPAT_ALTIVEC__
macro similarly to other instances of incompatibility.
Differential revision: https://reviews.llvm.org/D113642
Currently, FPSCR is not modeled, so in some early passes (such as
early-cse), the read/set intrinsics to FPSCR may get incorrect
simplification.
Reviewed By: jsji
Differential Revision: https://reviews.llvm.org/D112380
This patch introduces two intrinsics: llvm.ppc.setflm and
llvm.ppc.readflm. They read from or write to FPSCR register
(floating-point status & control) which contains rounding mode and
exception status.
To ensure correctness of program, we need to prevent FP operations from
being moved across these intrinsics (mffs/mtfsf instruction), so here I
set them as scheduling boundaries. We can relax such restriction if
FPSCR is modeled well in the future.
Reviewed By: steven.zhang
Differential Revision: https://reviews.llvm.org/D84914
