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Pettenò: Debunking x32 myths

Pettenò: Debunking x32 myths

Posted Jun 26, 2012 11:47 UTC (Tue) by mansr (guest, #85328)
In reply to: Pettenò: Debunking x32 myths by k3ninho
Parent article: Pettenò: Debunking x32 myths

> [Thumb] cuts down the instructions as well as the data to 16-bit symbols

Wrong. The original Thumb instruction set has 16-bit instructions with reduced functionality, most notably many instructions can access only the low 8 registers. The register size is still 32 bits. Thumb2 extends the instruction set with additional 32-bit instructions providing full access to the entire architecture.

The 64-bit ARM has no equivalent of Thumb mode, although 32-bit ARMv7 userspace is still supported.

See http://www.arm.com/files/downloads/ARMv8_Architecture.pdf for more information.


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