[X86] Fix stack alignment for MCU target

[anadolskiy]

Summary

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

[anadolskiy]

ping

[anadolskiy]

ping

[anadolskiy]

ping

[anadolskiy]

ping

[anadolskiy]

ping

[nadav]

Sorry for the delay in review. This patch LGTM.

llvm/trunk/lib/Target/X86/X86TargetMachine.cpp

static std::string computeDataLayout(const Triple &TT) {
   if ((TT.isArch64Bit() &&
        (TT.getEnvironment() == Triple::GNUX32 || TT.isOSNaCl())) ||
       !TT.isArch64Bit())
     Ret += "-p:32:32";
 
   // 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";
   else
     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";
 
   return Ret;
 }
 
 /// X86TargetMachine ctor - Create an X86 target.

llvm/trunk/test/CodeGen/X86/mcu-abi.ll

 ; CHECK-LABEL: var_args:
 ; CHECK: movl    4(%esp), %eax
 ; CHECK-NEXT: retl
 define i32 @var_args(i32 %i1, ...) #0 {
 entry:
   ret i32 %i1
 }
 
+%struct.S = type { i8 }
+
 ; CHECK-LABEL: test_lib_args:
 ; CHECK: movl %edx, %eax
 ; CHECK: calll __fixsfsi
 define i32 @test_lib_args(float %a, float %b) #0 {
   %ret = fptosi float %b to i32
   ret i32 %ret
 }
 

 define i32 @test_fp128(fp128* %ptr) #0 {
   %v = load fp128, fp128* %ptr
   %ret = fptosi fp128 %v to i32
   ret i32 %ret
 }
 
 declare void @llvm.memcpy.p0i8.p0i8.i32(i8* nocapture, i8* nocapture readonly, i32, i32, i1) #1
 
+; CHECK-LABEL: test_alignment_d:
+; CHECK-NOT: andl  {{.+}}, %esp
+define void @test_alignment_d() #0 {
+entry:
+  %d = alloca double
+  store double 2.000000e+00, double* %d
+  call void @food(double* inreg %d) 
+  ret void
+}
+
+; CHECK-LABEL: test_alignment_i:
+; CHECK-NOT: andl  {{.+}}, %esp
+define void @test_alignment_i() #0 {
+entry:
+  %i = alloca i64
+  store i64 2, i64* %i
+  call void @fooi(i64* inreg %i) 
+  ret void
+}
+
+
+; CHECK-LABEL: test_alignment_s:
+; CHECK-NOT: andl  {{.+}}, %esp
+define void @test_alignment_s() #0 {
+  %s = alloca %struct.S, align 4
+  call void @foos(%struct.S* inreg %s) 
+  ret void
+}
+
+
+; CHECK-LABEL: test_alignment_fp:
+; CHECK-NOT: andl  {{.+}}, %esp
+define void @test_alignment_fp() #0 {
+entry:
+  %f = alloca fp128
+  store fp128 0xL00000000000000004000000000000000, fp128* %f
+  call void @foofp(fp128* inreg %f)
+  ret void
+}
+
+declare void @food(double* inreg)
+declare void @fooi(i64* inreg)
+declare void @foos(%struct.S* inreg)
+declare void @foofp(fp128* inreg)
+
 attributes #0 = { nounwind "use-soft-float"="true"}
 attributes #1 = { nounwind argmemonly }