In this patch, we teach X86_64TargetMachine that it has a ILP32

(defined by the x32 ABI) mode, in which case its pointers are 32-bits
in size. This knowledge is also added to X86RegisterInfo that now
returns the appropriate registers in getPointerRegClass.

There are many outcomes to this change. In order to keep the patches
separate and manageable, we start by focusing on some simple testable
cases. The patch adds a test with passing a pointer to a function -
focusing on the difference between the two data models for x86-64.
Another test is added for handling of 'sret' arguments (and
functionality is added in X86ISelLowering to make it work).

A note on naming: the "x32 ABI" document refers to the AMD64
architecture (in LLVM it's distinguished by being is64Bits() in the
x86 subtarget) with two variations: the LP64 (default) data model, and
the ILP32 data model. This patch adds predicates to the subtarget
which are consistent with this naming scheme.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173503 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 43 insertions, 4 deletions

diff --git a/test/CodeGen/X86/x86-64-ptr-arg-simple.ll b/test/CodeGen/X86/x86-64-ptr-arg-simple.ll
new file mode 100644
index 0000000000..6d46663989
--- /dev/null
+++ b/test/CodeGen/X86/x86-64-ptr-arg-simple.ll
@@ -0,0 +1,29 @@
+; RUN: llc -mtriple=x86_64-pc-linux < %s | FileCheck %s
+; RUN: llc -mtriple=x86_64-pc-linux-gnux32 < %s | FileCheck -check-prefix=X32ABI %s
+
+; %in is kept in %esi for both ABIs. But the pointer will be passed in %edi
+; for x32, not %rdi
+
+; CHECK: movl %esi, (%rdi)
+; X32ABI: movl %esi, (%edi)
+
+define void @foo(i32* nocapture %out, i32 %in) nounwind {
+entry:
+  store i32 %in, i32* %out, align 4
+  ret void
+}
+
+; CHECK: bar
+; CHECK: movl (%rsi), %eax
+
+; Similarly here, but for loading
+; X32ABI: bar
+; X32ABI: movl (%esi), %eax
+
+define void @bar(i32* nocapture %pOut, i32* nocapture %pIn) nounwind {
+entry:
+  %0 = load i32* %pIn, align 4
+  store i32 %0, i32* %pOut, align 4
+  ret void
+}
+
diff --git a/test/CodeGen/X86/x86-64-sret-return.ll b/test/CodeGen/X86/x86-64-sret-return.ll
index 7b5f189faa..bc8a543465 100644
--- a/test/CodeGen/X86/x86-64-sret-return.ll
+++ b/test/CodeGen/X86/x86-64-sret-return.ll
@@ -1,11 +1,16 @@
-; RUN: llc < %s | FileCheck %s
+; RUN: llc -mtriple=x86_64-apple-darwin8 < %s | FileCheck %s
+; RUN: llc -mtriple=x86_64-pc-linux < %s | FileCheck %s
+; RUN: llc -mtriple=x86_64-pc-linux-gnux32 < %s | FileCheck -check-prefix=X32ABI %s
 
-target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128"
-target triple = "x86_64-apple-darwin8"
-	%struct.foo = type { [4 x i64] }
+%struct.foo = type { [4 x i64] }
 
 ; CHECK: bar:
 ; CHECK: movq %rdi, %rax
+
+; For the x32 ABI, pointers are 32-bit so 32-bit instructions will be used
+; X32ABI: bar:
+; X32ABI: movl %edi, %eax
+
 define void @bar(%struct.foo* noalias sret  %agg.result, %struct.foo* %d) nounwind  {
 entry:
 	%d_addr = alloca %struct.foo*		; <%struct.foo**> [#uses=2]
@@ -57,6 +62,11 @@ return:		; preds = %entry
 
 ; CHECK: foo:
 ; CHECK: movq %rdi, %rax
+
+; For the x32 ABI, pointers are 32-bit so 32-bit instructions will be used
+; X32ABI: foo:
+; X32ABI: movl %edi, %eax
+
 define void @foo({ i64 }* noalias nocapture sret %agg.result) nounwind {
   store { i64 } { i64 0 }, { i64 }* %agg.result
   ret void