X86: expand atomics in IR instead of as MachineInstrs.

The logic for expanding atomics that aren't natively supported in
terms of cmpxchg loops is much simpler to express at the IR level. It
also allows the normal optimisations and CodeGen improvements to help
out with atomics, instead of using a limited set of possible
instructions..

rdar://problem/13496295

llvm-svn: 212119

1 files changed, 51 insertions, 28 deletions

diff --git a/llvm/test/CodeGen/X86/atomic8.ll b/llvm/test/CodeGen/X86/atomic8.ll
index 203b26f0ab9..5eef9b295e8 100644
--- a/llvm/test/CodeGen/X86/atomic8.ll
+++ b/llvm/test/CodeGen/X86/atomic8.ll
@@ -4,8 +4,8 @@
 @sc8 = external global i8
 
 define void @atomic_fetch_add8() nounwind {
-; X64:   atomic_fetch_add8
-; X32:   atomic_fetch_add8
+; X64-LABEL:   atomic_fetch_add8:
+; X32-LABEL:   atomic_fetch_add8:
 entry:
 ; 32-bit
   %t1 = atomicrmw add  i8* @sc8, i8 1 acquire
@@ -34,8 +34,8 @@ entry:
 }
 
 define void @atomic_fetch_sub8() nounwind {
-; X64:   atomic_fetch_sub8
-; X32:   atomic_fetch_sub8
+; X64-LABEL:   atomic_fetch_sub8:
+; X32-LABEL:   atomic_fetch_sub8:
   %t1 = atomicrmw sub  i8* @sc8, i8 1 acquire
 ; X64:       lock
 ; X64:       decb
@@ -62,8 +62,8 @@ define void @atomic_fetch_sub8() nounwind {
 }
 
 define void @atomic_fetch_and8() nounwind {
-; X64:   atomic_fetch_and8
-; X32:   atomic_fetch_and8
+; X64-LABEL:   atomic_fetch_and8:
+; X32-LABEL:   atomic_fetch_and8:
   %t1 = atomicrmw and  i8* @sc8, i8 3 acquire
 ; X64:       lock
 ; X64:       andb $3
@@ -87,8 +87,8 @@ define void @atomic_fetch_and8() nounwind {
 }
 
 define void @atomic_fetch_or8() nounwind {
-; X64:   atomic_fetch_or8
-; X32:   atomic_fetch_or8
+; X64-LABEL:   atomic_fetch_or8:
+; X32-LABEL:   atomic_fetch_or8:
   %t1 = atomicrmw or   i8* @sc8, i8 3 acquire
 ; X64:       lock
 ; X64:       orb $3
@@ -112,8 +112,8 @@ define void @atomic_fetch_or8() nounwind {
 }
 
 define void @atomic_fetch_xor8() nounwind {
-; X64:   atomic_fetch_xor8
-; X32:   atomic_fetch_xor8
+; X64-LABEL:   atomic_fetch_xor8:
+; X32-LABEL:   atomic_fetch_xor8:
   %t1 = atomicrmw xor  i8* @sc8, i8 3 acquire
 ; X64:       lock
 ; X64:       xorb $3
@@ -137,8 +137,8 @@ define void @atomic_fetch_xor8() nounwind {
 }
 
 define void @atomic_fetch_nand8(i8 %x) nounwind {
-; X64:   atomic_fetch_nand8
-; X32:   atomic_fetch_nand8
+; X64-LABEL:   atomic_fetch_nand8:
+; X32-LABEL:   atomic_fetch_nand8:
   %t1 = atomicrmw nand i8* @sc8, i8 %x acquire
 ; X64:       andb
 ; X64:       notb
@@ -154,14 +154,18 @@ define void @atomic_fetch_nand8(i8 %x) nounwind {
 }
 
 define void @atomic_fetch_max8(i8 %x) nounwind {
+; X64-LABEL:   atomic_fetch_max8:
+; X32-LABEL:   atomic_fetch_max8:
   %t1 = atomicrmw max  i8* @sc8, i8 %x acquire
-; X64:       cmpb
-; X64:       cmov
+; X64:       movsbl
+; X64:       movsbl
+; X64:       subl
 ; X64:       lock
 ; X64:       cmpxchgb
 
-; X32:       cmpb
-; X32:       cmov
+; X32:       movsbl
+; X32:       movsbl
+; X32:       subl
 ; X32:       lock
 ; X32:       cmpxchgb
   ret void
@@ -170,14 +174,18 @@ define void @atomic_fetch_max8(i8 %x) nounwind {
 }
 
 define void @atomic_fetch_min8(i8 %x) nounwind {
+; X64-LABEL:   atomic_fetch_min8:
+; X32-LABEL:   atomic_fetch_min8:
   %t1 = atomicrmw min  i8* @sc8, i8 %x acquire
-; X64:       cmpb
-; X64:       cmov
+; X64:       movsbl
+; X64:       movsbl
+; X64:       subl
 ; X64:       lock
 ; X64:       cmpxchgb
 
-; X32:       cmpb
-; X32:       cmov
+; X32:       movsbl
+; X32:       movsbl
+; X32:       subl
 ; X32:       lock
 ; X32:       cmpxchgb
   ret void
@@ -186,14 +194,18 @@ define void @atomic_fetch_min8(i8 %x) nounwind {
 }
 
 define void @atomic_fetch_umax8(i8 %x) nounwind {
+; X64-LABEL:   atomic_fetch_umax8:
+; X32-LABEL:   atomic_fetch_umax8:
   %t1 = atomicrmw umax i8* @sc8, i8 %x acquire
-; X64:       cmpb
-; X64:       cmov
+; X64:       movzbl
+; X64:       movzbl
+; X64:       subl
 ; X64:       lock
 ; X64:       cmpxchgb
 
-; X32:       cmpb
-; X32:       cmov
+; X32:       movzbl
+; X32:       movzbl
+; X32:       subl
 ; X32:       lock
 ; X32:       cmpxchgb
   ret void
@@ -202,13 +214,18 @@ define void @atomic_fetch_umax8(i8 %x) nounwind {
 }
 
 define void @atomic_fetch_umin8(i8 %x) nounwind {
+; X64-LABEL:   atomic_fetch_umin8:
+; X32-LABEL:   atomic_fetch_umin8:
   %t1 = atomicrmw umin i8* @sc8, i8 %x acquire
-; X64:       cmpb
-; X64:       cmov
+; X64:       movzbl
+; X64:       movzbl
+; X64:       subl
 ; X64:       lock
 ; X64:       cmpxchgb
-; X32:       cmpb
-; X32:       cmov
+
+; X32:       movzbl
+; X32:       movzbl
+; X32:       subl
 ; X32:       lock
 ; X32:       cmpxchgb
   ret void
@@ -217,6 +234,8 @@ define void @atomic_fetch_umin8(i8 %x) nounwind {
 }
 
 define void @atomic_fetch_cmpxchg8() nounwind {
+; X64-LABEL:   atomic_fetch_cmpxchg8:
+; X32-LABEL:   atomic_fetch_cmpxchg8:
   %t1 = cmpxchg i8* @sc8, i8 0, i8 1 acquire acquire
 ; X64:       lock
 ; X64:       cmpxchgb
@@ -228,6 +247,8 @@ define void @atomic_fetch_cmpxchg8() nounwind {
 }
 
 define void @atomic_fetch_store8(i8 %x) nounwind {
+; X64-LABEL:   atomic_fetch_store8:
+; X32-LABEL:   atomic_fetch_store8:
   store atomic i8 %x, i8* @sc8 release, align 4
 ; X64-NOT:   lock
 ; X64:       movb
@@ -239,6 +260,8 @@ define void @atomic_fetch_store8(i8 %x) nounwind {
 }
 
 define void @atomic_fetch_swap8(i8 %x) nounwind {
+; X64-LABEL:   atomic_fetch_swap8:
+; X32-LABEL:   atomic_fetch_swap8:
   %t1 = atomicrmw xchg i8* @sc8, i8 %x acquire
 ; X64-NOT:   lock
 ; X64:       xchgb