fallback: legalize: G

fallback: legalize: G_ADD <8 x s8>

Run:	main-04ca53e65f-20261014-105623
Kind:	fallback
Category:	legalize: G_ADD <8 x s8>
Occurrences:	26 in 21 configs, 6 test files
Snippet from:	rvp-simd-64.ll @test_padd_b via llvm-extract
Config:	`-mtriple=riscv64 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs`
Local check:	reproduces at 04ca53e65f
Compiler Explorer:	not uploaded (over --godbolt-limit or disabled)

Snippet:

define <8 x i8> @test_padd_b(<8 x i8> %a, <8 x i8> %b) {
  %res = add <8 x i8> %a, %b
  ret <8 x i8> %res
}

Reproduce:

llc -mtriple=riscv64 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.* snippet.ll -o -
llc -mtriple=riscv64 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs -global-isel=0 snippet.ll -o -

Local llc output:

remark: <unknown>:0:0: unable to legalize instruction: %2:_(<8 x s8>) = G_ADD %0:_, %1:_ (in function: test_padd_b)
warning: Instruction selection used fallback path for test_padd_b

Occurrences (26):

Input	Function	Config
calling-conv-p-ext-vector.ll	test_cc_v8i8	`-mtriple=riscv64 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs`
rvp-simd-64.ll	test_padd_b	`-mtriple=riscv64 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs`
rvp-simd-64.ll	test_paaddu_b	`-mtriple=riscv64 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs`
rvp-simd-64.ll	test_padd_bs_splat_lhs	`-mtriple=riscv64 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs`
rvp-simd-64.ll	test_padd_bs_splat_rhs	`-mtriple=riscv64 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs`
calling-conv-p-ext-vector.883bef211a.ll (mutant of calling-conv-p-ext-vector.ll)	test_cc_v8i8	`-mtriple=riscv64 -mattr=+experimental-p,+m,+zbb -verify-machineinstrs`
dwarf-eh.1951660281.ll (mutant of dwarf-eh.ll)	test1	`-mtriple=riscv32 --code-model=small`
dwarf-eh.2bd869db75.ll (mutant of dwarf-eh.ll)	test1	`-mtriple=riscv32 --code-model=medium`
dwarf-eh.7e32915a4b.ll (mutant of dwarf-eh.ll)	test1	`-mtriple=riscv64 --code-model=small`
dwarf-eh.92d7aa2de9.ll (mutant of dwarf-eh.ll)	test1	`-mtriple=riscv64 --code-model=medium -relocation-model=pic`
dwarf-eh.a0ab1c1444.ll (mutant of dwarf-eh.ll)	test1	`-mtriple=riscv32 --code-model=medium -relocation-model=pic`
dwarf-eh.ab1774b512.ll (mutant of dwarf-eh.ll)	test1	`-mtriple=riscv32 --code-model=small -relocation-model=pic`
dwarf-eh.b3b7ebb465.ll (mutant of dwarf-eh.ll)	test1	`-mtriple=riscv64 --code-model=medium`
dwarf-eh.c871a4c924.ll (mutant of dwarf-eh.ll)	test1	`-mtriple=riscv64 --code-model=small -relocation-model=pic`
forced-atomics.5663c9d557.ll (mutant of forced-atomics.ll)	load32_unordered	`-mtriple=riscv32 -mattr=+forced-atomics,+no-trailing-seq-cst-fence`
forced-atomics.7dcd496fe2.ll (mutant of forced-atomics.ll)	load32_unordered	`-mtriple=riscv32 -mattr=+forced-atomics`
forced-atomics.8eda6fac19.ll (mutant of forced-atomics.ll)	load32_unordered	`-mtriple=riscv64 -mattr=+forced-atomics,+no-trailing-seq-cst-fence`
forced-atomics.ac53dcc3d3.ll (mutant of forced-atomics.ll)	load32_unordered	`-mtriple=riscv32`
forced-atomics.b40cc0affe.ll (mutant of forced-atomics.ll)	load32_unordered	`-mtriple=riscv64`
forced-atomics.b57f2fdb60.ll (mutant of forced-atomics.ll)	load32_unordered	`-mtriple=riscv64 -mattr=+no-trailing-seq-cst-fence`
forced-atomics.e4d49f87e5.ll (mutant of forced-atomics.ll)	load32_unordered	`-mtriple=riscv64 -mattr=+forced-atomics`
forced-atomics.f1d8109849.ll (mutant of forced-atomics.ll)	load32_unordered	`-mtriple=riscv32 -mattr=+no-trailing-seq-cst-fence`
inline-asm-d-abi-names.9d3b281a53.ll (mutant of inline-asm-d-abi-names.ll)	explicit_register_f4	`-mtriple=riscv64 -mattr=+f,+d -target-abi lp64d -verify-machineinstrs`
inline-asm-d-abi-names.aabb54ba0c.ll (mutant of inline-asm-d-abi-names.ll)	explicit_register_f4	`-mtriple=riscv32 -mattr=+f,+d -target-abi ilp32d -verify-machineinstrs`
inline-asm-f-abi-names.620cf1dd68.ll (mutant of inline-asm-f-abi-names.ll)	explicit_register_f4	`-mtriple=riscv64 -mattr=+f -target-abi lp64f -verify-machineinstrs`
inline-asm-f-abi-names.72d653f2a6.ll (mutant of inline-asm-f-abi-names.ll)	explicit_register_f4	`-mtriple=riscv32 -mattr=+f -target-abi ilp32f -verify-machineinstrs`

Generated 2026-10-15 08:05 UTC.