llvm-6502/test/CodeGen/SystemZ/cmpxchg-03.ll
Tim Northover 8f2a85e099 IR: add "cmpxchg weak" variant to support permitted failure.
This commit adds a weak variant of the cmpxchg operation, as described
in C++11. A cmpxchg instruction with this modifier is permitted to
fail to store, even if the comparison indicated it should.

As a result, cmpxchg instructions must return a flag indicating
success in addition to their original iN value loaded. Thus, for
uniformity *all* cmpxchg instructions now return "{ iN, i1 }". The
second flag is 1 when the store succeeded.

At the DAG level, a new ATOMIC_CMP_SWAP_WITH_SUCCESS node has been
added as the natural representation for the new cmpxchg instructions.
It is a strong cmpxchg.

By default this gets Expanded to the existing ATOMIC_CMP_SWAP during
Legalization, so existing backends should see no change in behaviour.
If they wish to deal with the enhanced node instead, they can call
setOperationAction on it. Beware: as a node with 2 results, it cannot
be selected from TableGen.

Currently, no use is made of the extra information provided in this
patch. Test updates are almost entirely adapting the input IR to the
new scheme.

Summary for out of tree users:
------------------------------

+ Legacy Bitcode files are upgraded during read.
+ Legacy assembly IR files will be invalid.
+ Front-ends must adapt to different type for "cmpxchg".
+ Backends should be unaffected by default.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210903 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-13 14:24:07 +00:00

144 lines
4.3 KiB
LLVM

; Test 32-bit compare and swap.
;
; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
; Check the low end of the CS range.
define i32 @f1(i32 %cmp, i32 %swap, i32 *%src) {
; CHECK-LABEL: f1:
; CHECK: cs %r2, %r3, 0(%r4)
; CHECK: br %r14
%pair = cmpxchg i32 *%src, i32 %cmp, i32 %swap seq_cst seq_cst
%val = extractvalue { i32, i1 } %pair, 0
ret i32 %val
}
; Check the high end of the aligned CS range.
define i32 @f2(i32 %cmp, i32 %swap, i32 *%src) {
; CHECK-LABEL: f2:
; CHECK: cs %r2, %r3, 4092(%r4)
; CHECK: br %r14
%ptr = getelementptr i32 *%src, i64 1023
%pair = cmpxchg i32 *%ptr, i32 %cmp, i32 %swap seq_cst seq_cst
%val = extractvalue { i32, i1 } %pair, 0
ret i32 %val
}
; Check the next word up, which should use CSY instead of CS.
define i32 @f3(i32 %cmp, i32 %swap, i32 *%src) {
; CHECK-LABEL: f3:
; CHECK: csy %r2, %r3, 4096(%r4)
; CHECK: br %r14
%ptr = getelementptr i32 *%src, i64 1024
%pair = cmpxchg i32 *%ptr, i32 %cmp, i32 %swap seq_cst seq_cst
%val = extractvalue { i32, i1 } %pair, 0
ret i32 %val
}
; Check the high end of the aligned CSY range.
define i32 @f4(i32 %cmp, i32 %swap, i32 *%src) {
; CHECK-LABEL: f4:
; CHECK: csy %r2, %r3, 524284(%r4)
; CHECK: br %r14
%ptr = getelementptr i32 *%src, i64 131071
%pair = cmpxchg i32 *%ptr, i32 %cmp, i32 %swap seq_cst seq_cst
%val = extractvalue { i32, i1 } %pair, 0
ret i32 %val
}
; Check the next word up, which needs separate address logic.
; Other sequences besides this one would be OK.
define i32 @f5(i32 %cmp, i32 %swap, i32 *%src) {
; CHECK-LABEL: f5:
; CHECK: agfi %r4, 524288
; CHECK: cs %r2, %r3, 0(%r4)
; CHECK: br %r14
%ptr = getelementptr i32 *%src, i64 131072
%pair = cmpxchg i32 *%ptr, i32 %cmp, i32 %swap seq_cst seq_cst
%val = extractvalue { i32, i1 } %pair, 0
ret i32 %val
}
; Check the high end of the negative aligned CSY range.
define i32 @f6(i32 %cmp, i32 %swap, i32 *%src) {
; CHECK-LABEL: f6:
; CHECK: csy %r2, %r3, -4(%r4)
; CHECK: br %r14
%ptr = getelementptr i32 *%src, i64 -1
%pair = cmpxchg i32 *%ptr, i32 %cmp, i32 %swap seq_cst seq_cst
%val = extractvalue { i32, i1 } %pair, 0
ret i32 %val
}
; Check the low end of the CSY range.
define i32 @f7(i32 %cmp, i32 %swap, i32 *%src) {
; CHECK-LABEL: f7:
; CHECK: csy %r2, %r3, -524288(%r4)
; CHECK: br %r14
%ptr = getelementptr i32 *%src, i64 -131072
%pair = cmpxchg i32 *%ptr, i32 %cmp, i32 %swap seq_cst seq_cst
%val = extractvalue { i32, i1 } %pair, 0
ret i32 %val
}
; Check the next word down, which needs separate address logic.
; Other sequences besides this one would be OK.
define i32 @f8(i32 %cmp, i32 %swap, i32 *%src) {
; CHECK-LABEL: f8:
; CHECK: agfi %r4, -524292
; CHECK: cs %r2, %r3, 0(%r4)
; CHECK: br %r14
%ptr = getelementptr i32 *%src, i64 -131073
%pair = cmpxchg i32 *%ptr, i32 %cmp, i32 %swap seq_cst seq_cst
%val = extractvalue { i32, i1 } %pair, 0
ret i32 %val
}
; Check that CS does not allow an index.
define i32 @f9(i32 %cmp, i32 %swap, i64 %src, i64 %index) {
; CHECK-LABEL: f9:
; CHECK: agr %r4, %r5
; CHECK: cs %r2, %r3, 0(%r4)
; CHECK: br %r14
%add1 = add i64 %src, %index
%ptr = inttoptr i64 %add1 to i32 *
%pair = cmpxchg i32 *%ptr, i32 %cmp, i32 %swap seq_cst seq_cst
%val = extractvalue { i32, i1 } %pair, 0
ret i32 %val
}
; Check that CSY does not allow an index.
define i32 @f10(i32 %cmp, i32 %swap, i64 %src, i64 %index) {
; CHECK-LABEL: f10:
; CHECK: agr %r4, %r5
; CHECK: csy %r2, %r3, 4096(%r4)
; CHECK: br %r14
%add1 = add i64 %src, %index
%add2 = add i64 %add1, 4096
%ptr = inttoptr i64 %add2 to i32 *
%pair = cmpxchg i32 *%ptr, i32 %cmp, i32 %swap seq_cst seq_cst
%val = extractvalue { i32, i1 } %pair, 0
ret i32 %val
}
; Check that a constant %cmp value is loaded into a register first.
define i32 @f11(i32 %dummy, i32 %swap, i32 *%ptr) {
; CHECK-LABEL: f11:
; CHECK: lhi %r2, 1001
; CHECK: cs %r2, %r3, 0(%r4)
; CHECK: br %r14
%pair = cmpxchg i32 *%ptr, i32 1001, i32 %swap seq_cst seq_cst
%val = extractvalue { i32, i1 } %pair, 0
ret i32 %val
}
; Check that a constant %swap value is loaded into a register first.
define i32 @f12(i32 %cmp, i32 *%ptr) {
; CHECK-LABEL: f12:
; CHECK: lhi [[SWAP:%r[0-9]+]], 1002
; CHECK: cs %r2, [[SWAP]], 0(%r3)
; CHECK: br %r14
%pair = cmpxchg i32 *%ptr, i32 %cmp, i32 1002 seq_cst seq_cst
%val = extractvalue { i32, i1 } %pair, 0
ret i32 %val
}