fallback: legalize: G_SHL <4 x s32>

Run:explore-04ca53e65f-20261014-114124
Kind:fallback
Category:legalize: G_SHL <4 x s32> NEW
Occurrences:1 in 1 configs, 1 test files
Snippet from:xcvbitmanip.95b9698a4c.ll (mutant of xcvbitmanip.ll) @test.cv.bclrr via llvm-extract
Config:-O0 -mtriple=riscv32 -mattr=+xcvbitmanip -verify-machineinstrs
Local check:reproduces at 04ca53e65f
Compiler Explorer:not uploaded (over --godbolt-limit or disabled)

Snippet:

@G = external global <4 x i32>

define i32 @test.cv.bclrr(i32 %a, i32 %b) {
  %LGV = load <4 x i32>, ptr @G, align 16
  %1 = call i32 @llvm.riscv.cv.bitmanip.bclr(i32 %a, i32 %b)
  %B = shl <4 x i32> %LGV, zeroinitializer
  store <4 x i32> %B, ptr @G, align 16
  ret i32 %1
}

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare i32 @llvm.riscv.cv.bitmanip.bclr(i32, i32) #0

attributes #0 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }

Reproduce:

llc -O0 -mtriple=riscv32 -mattr=+xcvbitmanip -verify-machineinstrs -global-isel -global-isel-abort=2 -pass-remarks-missed=gisel.* snippet.ll -o -
llc -O0 -mtriple=riscv32 -mattr=+xcvbitmanip -verify-machineinstrs -global-isel=0 snippet.ll -o -

Local llc output:

remark: <unknown>:0:0: unable to legalize instruction: %7:_(<4 x s32>) = G_SHL %2:_, %5:_(<4 x s32>) (in function: test.cv.bclrr)
warning: Instruction selection used fallback path for test.cv.bclrr

Occurrences (1):

InputFunctionConfig
xcvbitmanip.95b9698a4c.ll (mutant of xcvbitmanip.ll)test.cv.bclrr-O0 -mtriple=riscv32 -mattr=+xcvbitmanip -verify-machineinstrs

Generated 2026-10-15 08:05 UTC.