x86_64 ABI: Account for sret parameters consuming an integer register.
- PR4242.
llvm-svn: 72268
diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp
index 356caa3..ce98f8c 100644
--- a/clang/lib/CodeGen/CGCall.cpp
+++ b/clang/lib/CodeGen/CGCall.cpp
@@ -1055,6 +1055,11 @@
// Keep track of the number of assigned registers.
unsigned freeIntRegs = 6, freeSSERegs = 8;
+
+ // If the return value is indirect, then the hidden argument is consuming one
+ // integer register.
+ if (FI.getReturnInfo().isIndirect())
+ --freeIntRegs;
// AMD64-ABI 3.2.3p3: Once arguments are classified, the registers
// get assigned (in left-to-right order) for passing as follows...