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--- en:multiasm:papc:chapter_6_4 [2025/05/15 11:51] – [Floating point values] ktokarz
+++ en:multiasm:papc:chapter_6_4 [2025/05/18 19:02] (current) – [Pointers] ktokarz
@@ Line 84: / Line 84: @@
 ===== Floating point vector data types =====
-Single precision
+Floating point vectors are formed with single or double precision packed data formats. They are processed by SSE or AVX instructions in a SIMD approach of processing. A 128-bit packed data format can store four single-precision data elements or two double-precision data elements. A 256-bit packed data format can store eight single-precision values or four double-precision values. A 512-bit packed data format can store sixteen single-precision values or eight double-precision values. These packed data types are shown in figure {{ref>packedfloattypes}}. Instructions operating on 16-bit half-precision values or Brain Floats can use twice as many such elements simultaneously in comparison to single-precision data.
-Double precision
+It is worth mentioning that some instructions operate on a single floating-point value, using only the lowest elements of the operands.
-Double extended precision
-Half precision
+<figure packedfloattypes>
-Brain Float
+{{ :en:multiasm:cs:packed_floats.png?800 |Illustration of packed floating point data types}}
+<caption>Pcked floating point data types in x64 architecture</caption>
+</figure>
+===== Bit field data type =====
+A bit field is a data type whose size is counted by the number of bits it occupies. The bit field can start at any bit position in the fundamental data type and can be up to 32 bits long. MASM supports it with the RECORD data type. The bit field type is shown in figure {{ref>bitfieldtype}}.
+<figure bitfieldtype>
+{{ :en:multiasm:cs:bit_field_type.png?300 |Illustration of bit field data type}}
+<caption>The bit field data type</caption>
+</figure>
+===== Pointers =====
+Pointers store the address of the memory which contains interesting information. They can point to the data or the instruction. If the segmentation is enabled, pointers can be near or far. The far pointer contains the logical address (formed with the segment and offset parts). The near pointer contains the offset only. The offset can be 16, 32 or 64 bits long. The segment selector is always stored as a 16-bit number. Illustration of possible pointer types is shown in figure {{ref>pointertypes}}.
+<figure pointertypes>
+{{ :en:multiasm:cs:pointers_types.png?600 |Illustration of near and far pointers types}}
+<caption>The near and far pointers types</caption>
+</figure>
+<note>
+The offset is often the result of complex addressing mode calculations and is called an effective address.
+</note>

en/multiasm/papc/chapter_6_4.1747309894.txt.gz · Last modified: 2025/05/15 11:51 by ktokarz