[PATCH] D28566: Disable Callee Saved Registers

Oren Ben Simhon via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Wed Feb 1 01:10:40 PST 2017

oren_ben_simhon added a comment.

I will create a wrapper function to be used instead of getCalleeSavedRegs().

Comment at: include/llvm/CodeGen/RegisterClassInfo.h:56
+  // runOnFunction() call. Used only to determine if an update was made.
+  SmallVector<uint8_t, 16> CalleeSavedRegs;
MatzeB wrote:
> There are several targets out there with more than 256 registers! AMDGPU already has > 1000, and I know of even crazier out-of-tree targets.
The size here is just the initial size. The size is updated according to the number of registers.

Notice that following code exmaple that actually changes the size (using push_back):

SmallVector<uint8_t, 16> ActualCalleeSaved;
  for (unsigned I = 0; unsigned Reg = CSR[I]; ++I)
    CalleeSavedRegs = ActualCalleeSaved;



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