Fix justify error for small structures in varargs for MIPS64BE

There was a problem when passing structures as variable arguments.
The structures smaller than 64 bit were not left justified on MIPS64
big endian. This is now fixed by shifting the value to make it left-
justified when appropriate.

This fixes the bug http://llvm.org/bugs/show_bug.cgi?id=21608

Patch by Aleksandar Beserminji.

Differential Revision: http://reviews.llvm.org/D7881

llvm-svn: 230657

1 files changed, 161 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/Mips/cconv/arguments-varargs-small-structs-multiple-args.ll b/llvm/test/CodeGen/Mips/cconv/arguments-varargs-small-structs-multiple-args.ll
new file mode 100644
index 00000000000..1f736252334
--- /dev/null
+++ b/llvm/test/CodeGen/Mips/cconv/arguments-varargs-small-structs-multiple-args.ll
@@ -0,0 +1,161 @@
+; RUN: llc --march=mips64 -mcpu=mips64r2 < %s | FileCheck %s
+
+; Generated from the C program:
+;  
+; #include <stdio.h>
+; #include <string.h>
+; 
+; struct SmallStruct_1b {
+;  char x1;
+; };
+; 
+; struct SmallStruct_2b {
+;  char x1;
+;  char x2;
+; };
+; 
+; struct SmallStruct_3b {
+;  char x1;
+;  char x2;
+;  char x3;
+; };
+; 
+; struct SmallStruct_4b {
+;  char x1;
+;  char x2;
+;  char x3;
+;  char x4;
+; };
+; 
+; struct SmallStruct_5b {
+;  char x1;
+;  char x2;
+;  char x3;
+;  char x4;
+;  char x5;
+; };
+; 
+; struct SmallStruct_6b {
+;  char x1;
+;  char x2;
+;  char x3;
+;  char x4;
+;  char x5;
+;  char x6;
+; };
+; 
+; struct SmallStruct_7b {
+;  char x1;
+;  char x2;
+;  char x3;
+;  char x4;
+;  char x5;
+;  char x6;
+;  char x7;
+; };
+; 
+; struct SmallStruct_8b {
+;  char x1;
+;  char x2;
+;  char x3;
+;  char x4;
+;  char x5;
+;  char x6;
+;  char x7;
+;  char x8;
+; };
+; 
+; struct SmallStruct_9b {
+;  char x1;
+;  char x2;
+;  char x3;
+;  char x4;
+;  char x5;
+;  char x6;
+;  char x7;
+;  char x8;
+;  char x9;
+; };
+; 
+; void varArgF_SmallStruct(char* c, ...);
+; 
+; void smallStruct_1b_x9(struct SmallStruct_1b* ss1,  struct SmallStruct_1b* ss2, struct SmallStruct_1b* ss3, struct SmallStruct_1b* ss4, struct SmallStruct_1b* ss5, struct SmallStruct_1b* ss6, struct SmallStruct_1b* ss7, struct SmallStruct_1b* ss8, struct SmallStruct_1b* ss9)
+; {
+;  varArgF_SmallStruct("", *ss1, *ss2, *ss3, *ss4, *ss5, *ss6, *ss7, *ss8, *ss9);
+; }
+
+%struct.SmallStruct_1b = type { i8 }
+
+@.str = private unnamed_addr constant [3 x i8] c"01\00", align 1
+
+declare void @varArgF_SmallStruct(i8* %c, ...) 
+
+define void @smallStruct_1b_x9(%struct.SmallStruct_1b* %ss1, %struct.SmallStruct_1b* %ss2, %struct.SmallStruct_1b* %ss3, %struct.SmallStruct_1b* %ss4, %struct.SmallStruct_1b* %ss5, %struct.SmallStruct_1b* %ss6, %struct.SmallStruct_1b* %ss7, %struct.SmallStruct_1b* %ss8, %struct.SmallStruct_1b* %ss9) #0 {
+entry:
+  %ss1.addr = alloca %struct.SmallStruct_1b*, align 8
+  %ss2.addr = alloca %struct.SmallStruct_1b*, align 8
+  %ss3.addr = alloca %struct.SmallStruct_1b*, align 8
+  %ss4.addr = alloca %struct.SmallStruct_1b*, align 8
+  %ss5.addr = alloca %struct.SmallStruct_1b*, align 8
+  %ss6.addr = alloca %struct.SmallStruct_1b*, align 8
+  %ss7.addr = alloca %struct.SmallStruct_1b*, align 8
+  %ss8.addr = alloca %struct.SmallStruct_1b*, align 8
+  %ss9.addr = alloca %struct.SmallStruct_1b*, align 8
+  store %struct.SmallStruct_1b* %ss1, %struct.SmallStruct_1b** %ss1.addr, align 8
+  store %struct.SmallStruct_1b* %ss2, %struct.SmallStruct_1b** %ss2.addr, align 8
+  store %struct.SmallStruct_1b* %ss3, %struct.SmallStruct_1b** %ss3.addr, align 8
+  store %struct.SmallStruct_1b* %ss4, %struct.SmallStruct_1b** %ss4.addr, align 8
+  store %struct.SmallStruct_1b* %ss5, %struct.SmallStruct_1b** %ss5.addr, align 8
+  store %struct.SmallStruct_1b* %ss6, %struct.SmallStruct_1b** %ss6.addr, align 8
+  store %struct.SmallStruct_1b* %ss7, %struct.SmallStruct_1b** %ss7.addr, align 8
+  store %struct.SmallStruct_1b* %ss8, %struct.SmallStruct_1b** %ss8.addr, align 8
+  store %struct.SmallStruct_1b* %ss9, %struct.SmallStruct_1b** %ss9.addr, align 8
+  %0 = load %struct.SmallStruct_1b** %ss1.addr, align 8
+  %1 = load %struct.SmallStruct_1b** %ss2.addr, align 8
+  %2 = load %struct.SmallStruct_1b** %ss3.addr, align 8
+  %3 = load %struct.SmallStruct_1b** %ss4.addr, align 8
+  %4 = load %struct.SmallStruct_1b** %ss5.addr, align 8
+  %5 = load %struct.SmallStruct_1b** %ss6.addr, align 8
+  %6 = load %struct.SmallStruct_1b** %ss7.addr, align 8
+  %7 = load %struct.SmallStruct_1b** %ss8.addr, align 8
+  %8 = load %struct.SmallStruct_1b** %ss9.addr, align 8
+  %9 = bitcast %struct.SmallStruct_1b* %0 to { i8 }*
+  %10 = getelementptr { i8 }* %9, i32 0, i32 0
+  %11 = load i8* %10, align 1
+  %12 = bitcast %struct.SmallStruct_1b* %1 to { i8 }*
+  %13 = getelementptr { i8 }* %12, i32 0, i32 0
+  %14 = load i8* %13, align 1
+  %15 = bitcast %struct.SmallStruct_1b* %2 to { i8 }*
+  %16 = getelementptr { i8 }* %15, i32 0, i32 0
+  %17 = load i8* %16, align 1
+  %18 = bitcast %struct.SmallStruct_1b* %3 to { i8 }*
+  %19 = getelementptr { i8 }* %18, i32 0, i32 0
+  %20 = load i8* %19, align 1
+  %21 = bitcast %struct.SmallStruct_1b* %4 to { i8 }*
+  %22 = getelementptr { i8 }* %21, i32 0, i32 0
+  %23 = load i8* %22, align 1
+  %24 = bitcast %struct.SmallStruct_1b* %5 to { i8 }*
+  %25 = getelementptr { i8 }* %24, i32 0, i32 0
+  %26 = load i8* %25, align 1
+  %27 = bitcast %struct.SmallStruct_1b* %6 to { i8 }*
+  %28 = getelementptr { i8 }* %27, i32 0, i32 0
+  %29 = load i8* %28, align 1
+  %30 = bitcast %struct.SmallStruct_1b* %7 to { i8 }*
+  %31 = getelementptr { i8 }* %30, i32 0, i32 0
+  %32 = load i8* %31, align 1
+  %33 = bitcast %struct.SmallStruct_1b* %8 to { i8 }*
+  %34 = getelementptr { i8 }* %33, i32 0, i32 0
+  %35 = load i8* %34, align 1
+  call void (i8*, ...)* @varArgF_SmallStruct(i8* getelementptr inbounds ([3 x i8]* @.str, i32 0, i32 0), i8 inreg %11, i8 inreg %14, i8 inreg %17, i8 inreg %20, i8 inreg %23, i8 inreg %26, i8 inreg %29, i8 inreg %32, i8 inreg %35)
+  ret void
+ ; CHECK-LABEL: smallStruct_1b_x9:
+ ; CHECK: dsll $[[R1:[0-9]+]], $[[R2:[0-9]+]], 56
+ ; CHECK: dsll $[[R1:[0-9]+]], $[[R2:[0-9]+]], 56
+ ; CHECK: dsll $[[R1:[0-9]+]], $[[R2:[0-9]+]], 56
+ ; CHECK: dsll $[[R1:[0-9]+]], $[[R2:[0-9]+]], 56
+ ; CHECK: dsll $[[R1:[0-9]+]], $[[R2:[0-9]+]], 56
+ ; CHECK: dsll $[[R1:[0-9]+]], $[[R2:[0-9]+]], 56
+ ; CHECK: dsll $[[R1:[0-9]+]], $[[R2:[0-9]+]], 56
+ ; CHECK: dsll $[[R1:[0-9]+]], $[[R2:[0-9]+]], 56
+ ; CHECK: dsll $[[R1:[0-9]+]], $[[R2:[0-9]+]], 56
+}