search for: stddw

...for loading does not point > to the address of the low word, but to the address of the high word. This is contradictory: on a little-endian processor, the address for loading a 64-bit value is same as the address of the low word. Are you sure you're modeling the semantics of your lddw and stddw instructions correctly? -Eli

> Hi Johannes, what processor are you targeting? Is it little-endian or > big-endian? Little-endian. (The truth: you can set it manually, but it is set to little endian, for sure.) The processor is a TI TMS320C64x. Follow-up: I discovered that the "guilty" method is DAGCombiner::ReduceLoadWidth. The error is introduced because the offset is not calculated correctly. The first

...load a singleword) gives an erroneous result. On my architecture, this results in the high bits being loaded into the return register, instead of the low bits, as should happen with truncate. Details: i64 's are stored in two adjacent 32 bit registers. So the store happens like this: "stddw 0xBBBBBBBB33333333, *$ptr" and the load should happen like this: "lddw *$ptr, A5:A4" . It is easy to see that if "ldw *$ptr, A4" is printed, then the high bits will be loaded into A4. Something like this would be correct just like the lddw variant: "ldw *-$ptr(4), A4&...

...an erroneous result. On my > architecture, this results in the high bits being loaded into the return > register, instead of the low bits, as should happen with truncate. > > Details: i64 's are stored in two adjacent 32 bit registers. So the > store happens like this: > "stddw 0xBBBBBBBB33333333, *$ptr" > and the load should happen like this: > "lddw *$ptr, A5:A4" > . It is easy to see that if > "ldw *$ptr, A4" > is printed, then the high bits will be loaded into A4. Something like > this would be correct just like the lddw vari...

> This is contradictory: on a little-endian processor, the address for > loading a 64-bit value is same as the address of the low word. Are > you sure you're modeling the semantics of your lddw and stddw > instructions correctly? ... I thought so until now. Because I implemented stdw (store doubleword) completely analogous to lddw: Just print out stdw with the given pointer and the register pair, just like lddw. (This seems obvious.) Well, ****. I just read the documentation very carefully (y...