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A comment on An ex-ARM engineer critiques RISC-V. Parent comment

Re:An ex-ARM engineer critiques RISC-V by loeg on Sunday November 01, 2020 @03:40PM (#24962314)
ARM had Thumb, right? Is that a deadend at this point?
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Re:An ex-ARM engineer critiques RISC-V by deaddodo on Sunday November 01, 2020 @09:47PM (#24964426)
Thumb was removed from ARMv8 (AArch64). If you use 32-but legacy, it may exist on some chips; but it’s no longer the benefit it once was.
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Re:An ex-ARM engineer critiques RISC-V by hajile on Monday November 02, 2020 @09:33AM (#24968475)
It's always been of the same value. You exchange performance for code density. They want aarch64 to be high-performance, so they removed thumb.

RISC-V compact instructions don't require special modes and run in fully-mixed mode with 32-bit instructions without all the penalties thumb has (they are literally just extended into their 32-bit counterparts internally).

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Re:An ex-ARM engineer critiques RISC-V by deaddodo on Monday November 02, 2020 @03:51PM (#24973162)
> It's always been of the same value. You exchange performance for code density.

High code density became less valuable, was the point.

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