diff options
Diffstat (limited to 'compiler/nativeGen/PPC/CodeGen.hs')
| -rw-r--r-- | compiler/nativeGen/PPC/CodeGen.hs | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/compiler/nativeGen/PPC/CodeGen.hs b/compiler/nativeGen/PPC/CodeGen.hs index d03a6e5c23..ead122b959 100644 --- a/compiler/nativeGen/PPC/CodeGen.hs +++ b/compiler/nativeGen/PPC/CodeGen.hs @@ -9,9 +9,8 @@ ----------------------------------------------------------------------------- -- This is a big module, but, if you pay attention to --- (a) the sectioning, (b) the type signatures, and --- (c) the #if blah_TARGET_ARCH} things, the --- structure should not be too overwhelming. +-- (a) the sectioning, and (b) the type signatures, +-- the structure should not be too overwhelming. module PPC.CodeGen ( cmmTopCodeGen, @@ -471,7 +470,8 @@ getRegister' _ (CmmMachOp (MO_UU_Conv W32 W64) [CmmLoad mem _]) = do return (Any II64 (\dst -> addr_code `snocOL` LD II32 dst addr)) getRegister' _ (CmmMachOp (MO_SS_Conv W32 W64) [CmmLoad mem _]) = do - Amode addr addr_code <- getAmode D mem + -- lwa is DS-form. See Note [Power instruction format] + Amode addr addr_code <- getAmode DS mem return (Any II64 (\dst -> addr_code `snocOL` LA II32 dst addr)) getRegister' dflags (CmmMachOp mop [x]) -- unary MachOps @@ -742,6 +742,14 @@ temporary, then do the other computation, and then use the temporary: ... (tmp) ... -} +{- Note [Power instruction format] +In some instructions the 16 bit offset must be a multiple of 4, i.e. +the two least significant bits mus be zero. The "Power ISA" specification +calls these instruction formats "DS-FORM" and the instructions with +arbitrary 16 bit offsets are "D-FORM". + +The Power ISA specification document can be obtained from www.power.org. +-} data InstrForm = D | DS getAmode :: InstrForm -> CmmExpr -> NatM Amode |