[X86] Fix stack alignment for MCU target, by Anton Nadolskiy.

This patch fixes stack alignments for MCU (should be aligned to 4 bytes).

Differential Revision: http://reviews.llvm.org/D15646

llvm-svn: 260375
diff --git a/llvm/lib/Target/X86/X86TargetMachine.cpp b/llvm/lib/Target/X86/X86TargetMachine.cpp
index 0e7e4c0..9441daf 100644
--- a/llvm/lib/Target/X86/X86TargetMachine.cpp
+++ b/llvm/lib/Target/X86/X86TargetMachine.cpp
@@ -73,17 +73,22 @@
   // Some ABIs align 64 bit integers and doubles to 64 bits, others to 32.
   if (TT.isArch64Bit() || TT.isOSWindows() || TT.isOSNaCl())
     Ret += "-i64:64";
+  else if (TT.isOSIAMCU())
+    Ret += "-i64:32-f64:32";
   else
     Ret += "-f64:32:64";
 
   // Some ABIs align long double to 128 bits, others to 32.
-  if (TT.isOSNaCl())
+  if (TT.isOSNaCl() || TT.isOSIAMCU())
     ; // No f80
   else if (TT.isArch64Bit() || TT.isOSDarwin())
     Ret += "-f80:128";
   else
     Ret += "-f80:32";
 
+  if (TT.isOSIAMCU())
+    Ret += "-f128:32";
+
   // The registers can hold 8, 16, 32 or, in x86-64, 64 bits.
   if (TT.isArch64Bit())
     Ret += "-n8:16:32:64";
@@ -91,7 +96,7 @@
     Ret += "-n8:16:32";
 
   // The stack is aligned to 32 bits on some ABIs and 128 bits on others.
-  if (!TT.isArch64Bit() && TT.isOSWindows())
+  if ((!TT.isArch64Bit() && TT.isOSWindows()) || TT.isOSIAMCU())
     Ret += "-a:0:32-S32";
   else
     Ret += "-S128";