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Diffstat (limited to 'src/intro.tex')
| -rw-r--r-- | src/intro.tex | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/src/intro.tex b/src/intro.tex index 7448425..b95c6b3 100644 --- a/src/intro.tex +++ b/src/intro.tex @@ -326,9 +326,7 @@ single-precision computational instructions, and single-precision loads and stores. The standard double-precision floating-point extension, denoted by ``D'', expands the floating-point registers, and adds double-precision computational instructions, loads, and stores. -An integer base plus these four standard extensions (``IMAFD'') is -given the abbreviation ``G'' and provides a general-purpose scalar -instruction set. The standard ``C'' compressed instruction extension +The standard ``C'' compressed instruction extension provides narrower 16-bit forms of common instructions. Beyond the base integer ISA and the standard GC extensions, we believe @@ -536,7 +534,7 @@ support experimentation and larger instruction-set extensions. Although our encoding convention required a tighter encoding of the core RISC-V ISA, this has several beneficial effects. -An implementation of the standard G ISA need only hold the +An implementation of the standard IMAFD ISA need only hold the most-significant 30 bits in instruction caches (a 6.25\% saving). On instruction cache refills, any instructions encountered with either low bit clear should be recoded into illegal 30-bit instructions |