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| author | Ben Gamari <ben@well-typed.com> | 2022-06-23 12:41:12 -0400 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2022-06-28 03:24:24 -0400 |
| commit | 696d64c347364ce75e23d37884ec0bd2543b0a6a (patch) | |
| tree | d5c7686431a4a4e751cd462ecd16359ec78336d8 | |
| parent | 70f0c1f84213f7a09bc31e0eeefb5b089708f04b (diff) | |
| download | haskell-696d64c347364ce75e23d37884ec0bd2543b0a6a.tar.gz | |
CmmToAsm/AArch64: Sign-extend narrow C arguments
The AArch64/Darwin ABI requires that function arguments narrower
than 32-bits must be sign-extended by the caller. We neglected to
do this, resulting in #20735.
Fixes #20735.
| -rw-r--r-- | compiler/GHC/CmmToAsm/AArch64/CodeGen.hs | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/compiler/GHC/CmmToAsm/AArch64/CodeGen.hs b/compiler/GHC/CmmToAsm/AArch64/CodeGen.hs index 9509ffb467..0071f291a1 100644 --- a/compiler/GHC/CmmToAsm/AArch64/CodeGen.hs +++ b/compiler/GHC/CmmToAsm/AArch64/CodeGen.hs @@ -1620,9 +1620,21 @@ genCCall target dest_regs arg_regs bid = do -- size we want to pack. Failure to get this right can result in pretty -- subtle bugs, e.g. #20137. - passArguments pack (gpReg:gpRegs) fpRegs ((r, format, _hint, code_r):args) stackSpace accumRegs accumCode | isIntFormat format = do + passArguments pack (gpReg:gpRegs) fpRegs ((r, format, hint, code_r):args) stackSpace accumRegs accumCode | isIntFormat format = do + platform <- getPlatform let w = formatToWidth format - mov = MOV (OpReg w gpReg) (OpReg w r) + mov + -- Specifically, Darwin/AArch64's ABI requires that the caller + -- sign-extend arguments which are smaller than 32-bits. + | w < W32 + , platformCConvNeedsExtension platform + , SignedHint <- hint + = case w of + W8 -> SXTB (OpReg W64 gpReg) (OpReg w r) + W16 -> SXTH (OpReg W64 gpReg) (OpReg w r) + _ -> panic "impossible" + | otherwise + = MOV (OpReg w gpReg) (OpReg w r) accumCode' = accumCode `appOL` code_r `snocOL` ann (text "Pass gp argument: " <> ppr r) mov |