Finish rot/rotg/rotm to the BLAS reference (C8 part 2)#19
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The rotation routines existed but did not compile or build: srot used a struct-vs-int comparison and a uint32_t signature; srotg was WIP with the wrong sign factor (|roe| instead of sign(roe)) and assigned to local pointer copies; srotm had a parenless `if f32_eq(...)`. All were absent from the Makefile. Rewrite srot/srotg/srotm faithfully to the Netlib SROT/SROTG/SROTM reference using SoftFloat ops (loading operands into locals first, since the abs/compare macros don't parenthesize their argument), with NaN canonicalization on the outputs. Generate the float64 and float16 variants and add all nine to the Makefile. test_rot.c covers srot (c=0,s=1 -> (y,-x)), srotg (a=1,b=0; and 3,4 -> r=5), and srotm (flag=0 modified Givens). 155/155 tests pass. (rotmg and sdsdot/hsdot remain; rotmg's rescaling constant gamsq=2^24 overflows float16 and needs handling.) Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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The rotation routines existed but didn't compile or build. Rewritten faithfully to the Netlib
SROT/SROTG/SROTMreference and wired into the Makefile.uint32_tsignature. Now a clean strided plane rotation.|roe|instead ofsign(roe)) and assigned to local pointer copies. Now matches the reference (Givens generation,r,z).if f32_eq(...). Now applies the flag-selected modified-GivensH.Operands are loaded into locals first (the SoftFloat abs/compare macros don't parenthesize their argument), and outputs are NaN-canonicalized. float64/float16 variants generated; all nine added to the Makefile.
test_rot.c: srot (c=0,s=1 → (y,−x)), srotg (a=1,b=0; and3,4 → r=5), srotm (flag=0). 155/155.Remaining C8:
rotmg(whose rescale constantgamsq=2²⁴overflows float16) andsdsdot/hsdot.🤖 Generated with Claude Code