diff options
Diffstat (limited to 'compiler/GHC/Cmm/Node.hs')
| -rw-r--r-- | compiler/GHC/Cmm/Node.hs | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/compiler/GHC/Cmm/Node.hs b/compiler/GHC/Cmm/Node.hs index 31a3d14a86..01db60b116 100644 --- a/compiler/GHC/Cmm/Node.hs +++ b/compiler/GHC/Cmm/Node.hs @@ -93,7 +93,7 @@ data CmmNode e x where -- -- Invariant: the arguments and the ForeignTarget must not -- mention any registers for which GHC.Platform.callerSaves - -- is True. See Note [Register Parameter Passing]. + -- is True. See Note [Register parameter passing]. CmmBranch :: ULabel -> CmmNode O C -- Goto another block in the same procedure @@ -223,11 +223,12 @@ convention, rdi, rsi, rdx and rcx (as well as r8 and r9) may be used for argument passing. These are registers R3-R6, which our generated code may also be using; as a result, it's necessary to save these values before doing a foreign call. This is done during initial -code generation in callerSaveVolatileRegs in GHC.StgToCmm.Utils. However, -one result of doing this is that the contents of these registers -may mysteriously change if referenced inside the arguments. This -is dangerous, so you'll need to disable inlining much in the same -way is done in GHC.Cmm.Opt currently. We should fix this! +code generation in callerSaveVolatileRegs in GHC.StgToCmm.Utils. + +However, one result of doing this is that the contents of these registers may +mysteriously change if referenced inside the arguments. This is dangerous, so +you'll need to disable inlining much in the same way is done in GHC.Cmm.Sink +currently. We should fix this! -} --------------------------------------------- |