x86: Update branch hint for Redwood Cove.

According to Intel® 64 and IA-32 Architectures Optimization Reference
Manual[1], Branch Hint is updated for Redwood Cove.

--------cut from [1]-------------------------
Starting with the Redwood Cove microarchitecture, if the predictor has
no stored information about a branch, the branch has the Intel® SSE2
branch taken hint (i.e., instruction prefix 3EH), When the codec
decodes the branch, it flips the branch’s prediction from not-taken to
taken. It then flushes the pipeline in front of it and steers this
pipeline to fetch the taken path of the branch.
--------cut end -----------------------------

Split tune branch_prediction_hints into branch_prediction_hints_taken
and branch_prediction_hints_not_taken, always generate branch hint for
conditional branches, both tunes are disabled by default.

[1] https://www.intel.com/content/www/us/en/content-details/821612/intel-64-and-ia-32-architectures-optimization-reference-manual-volume-1.html

gcc/

	* config/i386/i386.cc (ix86_print_operand): Always generate
	branch hint for conditional branches.
	* config/i386/i386.h (TARGET_BRANCH_PREDICTION_HINTS): Split
	into ..
	(TARGET_BRANCH_PREDICTION_HINTS_TAKEN): .. this, and ..
	(TARGET_BRANCH_PREDICTION_HINTS_NOT_TAKEN): .. this.
	* config/i386/x86-tune.def (X86_TUNE_BRANCH_PREDICTION_HINTS):
	Split into ..
	(X86_TUNE_BRANCH_PREDICTION_HINTS_TAKEN): .. this, and ..
	(X86_TUNE_BRANCH_PREDICTION_HINTS_NOT_TAKEN): .. this.

0 files changed, 0 insertions, 0 deletions