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Check the correct value for small stack sizes. Also modify some comments. 

llvm-svn: 145954
This commit is contained in:
Bill Wendling 2011-12-06 19:16:17 +00:00
parent 8b815e1a08
commit 87571b6392
1 changed files with 8 additions and 5 deletions
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13
llvm/lib/Target/X86/X86FrameLowering.cpp
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@ -554,17 +554,17 @@ uint32_t X86FrameLowering::getCompactUnwindEncoding(MachineFunction &MF) const {
// Get the encoding of the saved registers when we have a frame pointer. // Get the encoding of the saved registers when we have a frame pointer.
uint32_t RegEnc = encodeCompactUnwindRegistersWithFrame(SavedRegs, Is64Bit); uint32_t RegEnc = encodeCompactUnwindRegistersWithFrame(SavedRegs, Is64Bit);
if (RegEnc == ~0U) if (RegEnc == ~0U) return 0;
return 0;
CompactUnwindEncoding |= 0x01000000; CompactUnwindEncoding |= 0x01000000;
CompactUnwindEncoding |= (CFAOffset & 0xFF) << 16; CompactUnwindEncoding |= (CFAOffset & 0xFF) << 16;
CompactUnwindEncoding |= RegEnc & 0x7FFF; CompactUnwindEncoding |= RegEnc & 0x7FFF;
} else { } else {
unsigned FullOffset = CFAOffset + StackAdjust; if ((CFAOffset & 0xFF) == CFAOffset) {
if ((FullOffset & 0xFF) == FullOffset) { // Frameless stack with a small stack size.
// Frameless stack.
CompactUnwindEncoding |= 0x02000000; CompactUnwindEncoding |= 0x02000000;
// Encode the stack size.
CompactUnwindEncoding |= (CFAOffset & 0xFF) << 16; CompactUnwindEncoding |= (CFAOffset & 0xFF) << 16;
} else { } else {
if ((CFAOffset & 0x7) != CFAOffset) if ((CFAOffset & 0x7) != CFAOffset)
@ -582,6 +582,7 @@ uint32_t X86FrameLowering::getCompactUnwindEncoding(MachineFunction &MF) const {
CompactUnwindEncoding |= (CFAOffset & 0x7) << 13; CompactUnwindEncoding |= (CFAOffset & 0x7) << 13;
} }
// Encode the number of registers saved.
CompactUnwindEncoding |= ((6 - SavedRegIdx) & 0x7) << 10; CompactUnwindEncoding |= ((6 - SavedRegIdx) & 0x7) << 10;
// Get the encoding of the saved registers when we don't have a frame // Get the encoding of the saved registers when we don't have a frame
@ -590,6 +591,8 @@ uint32_t X86FrameLowering::getCompactUnwindEncoding(MachineFunction &MF) const {
6 - SavedRegIdx, 6 - SavedRegIdx,
Is64Bit); Is64Bit);
if (RegEnc == ~0U) return 0; if (RegEnc == ~0U) return 0;
// Encode the register encoding.
CompactUnwindEncoding |= RegEnc & 0x3FF; CompactUnwindEncoding |= RegEnc & 0x3FF;
} }