Revert to extend i8/i16 return values on Darwin (PR26665)

In r260133, LLVM was changed to no longer extend i8/i16 return values,
as it's not required by the ABI. However, code was found in the wild
that relies on the old behaviour on Darwin, so this commit reverts
back to that old behaviour for Darwin.

On other platforms, it's less likely that code would be depending on
the old behaviour, as GCC and MSVC haven't been extending such return
values.

llvm-svn: 261235

4 files changed, 33 insertions, 11 deletions

diff --git a/llvm/test/CodeGen/X86/3addr-16bit.ll b/llvm/test/CodeGen/X86/3addr-16bit.ll
index 8cd45f793b7..2d6a5e76657 100644
--- a/llvm/test/CodeGen/X86/3addr-16bit.ll
+++ b/llvm/test/CodeGen/X86/3addr-16bit.ll
@@ -12,7 +12,7 @@ entry:
 
 ; 64BIT-LABEL:     t1:
 ; 64BIT-NOT: movw %si, %ax
-; 64BIT:     leal 1(%rsi), %ebx
+; 64BIT:     leal 1(%rsi), %eax
   %0 = icmp eq i16 %k, %c                         ; <i1> [#uses=1]
   %1 = add i16 %k, 1                              ; <i16> [#uses=3]
   br i1 %0, label %bb, label %bb1
@@ -34,8 +34,8 @@ entry:
 
 ; 64BIT-LABEL:     t2:
 ; 64BIT-NOT: movw %si, %ax
-; 64BIT:     leal -1(%rsi), %ebx
-; 64BIT:     movzwl %bx
+; 64BIT:     leal -1(%rsi), %eax
+; 64BIT:     movzwl %ax
   %0 = icmp eq i16 %k, %c                         ; <i1> [#uses=1]
   %1 = add i16 %k, -1                             ; <i16> [#uses=3]
   br i1 %0, label %bb, label %bb1
@@ -59,7 +59,7 @@ entry:
 
 ; 64BIT-LABEL:     t3:
 ; 64BIT-NOT: movw %si, %ax
-; 64BIT:     leal 2(%rsi), %ebx
+; 64BIT:     leal 2(%rsi), %eax
   %0 = add i16 %k, 2                              ; <i16> [#uses=3]
   %1 = icmp eq i16 %k, %c                         ; <i1> [#uses=1]
   br i1 %1, label %bb, label %bb1
@@ -82,7 +82,7 @@ entry:
 
 ; 64BIT-LABEL:     t4:
 ; 64BIT-NOT: movw %si, %ax
-; 64BIT:     leal (%rsi,%rdi), %ebx
+; 64BIT:     leal (%rsi,%rdi), %eax
   %0 = add i16 %k, %c                             ; <i16> [#uses=3]
   %1 = icmp eq i16 %k, %c                         ; <i1> [#uses=1]
   br i1 %1, label %bb, label %bb1
diff --git a/llvm/test/CodeGen/X86/divrem8_ext.ll b/llvm/test/CodeGen/X86/divrem8_ext.ll
index 59628518dab..b38797e2d9d 100644
--- a/llvm/test/CodeGen/X86/divrem8_ext.ll
+++ b/llvm/test/CodeGen/X86/divrem8_ext.ll
@@ -6,9 +6,9 @@ target triple = "x86_64-apple-macosx10.10.0"
 define zeroext i8 @test_udivrem_zext_ah(i8 %x, i8 %y) {
 ; CHECK-LABEL: test_udivrem_zext_ah
 ; CHECK:   divb
-; CHECK:   movzbl %ah, %e[[REG_REM:[a-z]]]x
+; CHECK:   movzbl %ah, [[REG_REM:%[a-z0-9]+]]
 ; CHECK:   movb   %al, ([[REG_ZPTR:%[a-z0-9]+]])
-; CHECK:   movb   %[[REG_REM]]l, %al
+; CHECK:   movl   [[REG_REM]], %eax
 ; CHECK:   ret
   %div = udiv i8 %x, %y
   store i8 %div, i8* @z
@@ -51,9 +51,9 @@ define signext i8 @test_sdivrem_sext_ah(i8 %x, i8 %y) {
 ; CHECK-LABEL: test_sdivrem_sext_ah
 ; CHECK:   cbtw
 ; CHECK:   idivb
-; CHECK:   movsbl %ah, %e[[REG_REM:[a-z]]]x
+; CHECK:   movsbl %ah, [[REG_REM:%[a-z0-9]+]]
 ; CHECK:   movb   %al, ([[REG_ZPTR]])
-; CHECK:   movb   %[[REG_REM]]l, %al
+; CHECK:   movl   [[REG_REM]], %eax
 ; CHECK:   ret
   %div = sdiv i8 %x, %y
   store i8 %div, i8* @z
diff --git a/llvm/test/CodeGen/X86/return-ext.ll b/llvm/test/CodeGen/X86/return-ext.ll
index fcdab81c898..8110addb943 100644
--- a/llvm/test/CodeGen/X86/return-ext.ll
+++ b/llvm/test/CodeGen/X86/return-ext.ll
@@ -1,5 +1,6 @@
 ; RUN: llc < %s -mtriple=i686-unknown-linux-gnu | FileCheck %s
 ; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu | FileCheck %s
+; RUN: llc < %s -mtriple=x86_64-apple-darwin | FileCheck -check-prefix=DARWIN %s
 
 
 @x = common global i32 0, align 4
@@ -29,6 +30,13 @@ entry:
 ; CHECK:			 cmp
 ; CHECK-NEXT:  sete
 ; CHECK-NEXT:  ret
+
+; Except on Darwin, for legacy reasons.
+; DARWIN-LABEL: unsigned_i8:
+; DARWIN:			  cmp
+; DARWIN-NEXT:  sete
+; DARWIN-NEXT:  movzbl
+; DARWIN-NEXT:  ret
 }
 
 define signext i8 @signed_i8() {
@@ -43,6 +51,13 @@ entry:
 ; CHECK:			 cmp
 ; CHECK-NEXT:  sete
 ; CHECK-NEXT:  ret
+
+; Except on Darwin, for legacy reasons.
+; DARWIN-LABEL: signed_i8:
+; DARWIN:			  cmp
+; DARWIN-NEXT:  sete
+; DARWIN-NEXT:  movzbl
+; DARWIN-NEXT:  ret
 }
 
 @a = common global i16 0
@@ -59,6 +74,13 @@ entry:
 ; CHECK:			 movw
 ; CHECK-NEXT:  addw
 ; CHECK-NEXT:  ret
+
+; Except on Darwin, for legay reasons.
+; DARWIN-LABEL: unsigned_i16:
+; DARWIN:	    	movw
+; DARWIN-NEXT:  addw
+; DARWIN-NEXT:  movzwl
+; DARWIN-NEXT:  ret
 }
 
 
diff --git a/llvm/test/CodeGen/X86/select.ll b/llvm/test/CodeGen/X86/select.ll
index b3f52673efe..a4e06b39844 100644
--- a/llvm/test/CodeGen/X86/select.ll
+++ b/llvm/test/CodeGen/X86/select.ll
@@ -66,10 +66,10 @@ entry:
 	%2 = load i8, i8* %1, align 1		; <i8> [#uses=1]
 	ret i8 %2
 ; CHECK-LABEL: test4:
-; CHECK: movb	({{.*}},4), %al
+; CHECK: movsbl	({{.*}},4), %eax
 
 ; ATOM-LABEL: test4:
-; ATOM: movb ({{.*}},4), %al
+; ATOM: movsbl ({{.*}},4), %eax
 }
 
 define void @test5(i1 %c, <2 x i16> %a, <2 x i16> %b, <2 x i16>* %p) nounwind {