llvm-6502/test/CodeGen/SystemZ/bswap-05.ll
Richard Sandiford b6606e46ab [SystemZ] Don't use LOAD and STORE REVERSED for volatile accesses
Unlike most -- hopefully "all other", but I'm still checking -- memory
instructions we support, LOAD REVERSED and STORE REVERSED may access
the memory location several times.  This means that they are not suitable
for volatile loads and stores.

This patch is a prerequisite for better atomic load and store support.
The same principle applies there: almost all memory instructions we
support are inherently atomic ("block concurrent"), but LOAD REVERSED
and STORE REVERSED are exceptions.

Other instructions continue to allow volatile operands.  I will add
positive "allows volatile" tests at the same time as the "allows atomic
load or store" tests.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183002 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-31 13:25:22 +00:00

100 lines
2.6 KiB
LLVM

; Test 64-bit byteswaps from registers to memory.
;
; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
declare i64 @llvm.bswap.i64(i64 %a)
; Check STRVG with no displacement.
define void @f1(i64 *%dst, i64 %a) {
; CHECK: f1:
; CHECK: strvg %r3, 0(%r2)
; CHECK: br %r14
%swapped = call i64 @llvm.bswap.i64(i64 %a)
store i64 %swapped, i64 *%dst
ret void
}
; Check the high end of the aligned STRVG range.
define void @f2(i64 *%dst, i64 %a) {
; CHECK: f2:
; CHECK: strvg %r3, 524280(%r2)
; CHECK: br %r14
%ptr = getelementptr i64 *%dst, i64 65535
%swapped = call i64 @llvm.bswap.i64(i64 %a)
store i64 %swapped, i64 *%ptr
ret void
}
; Check the next doubleword up, which needs separate address logic.
; Other sequences besides this one would be OK.
define void @f3(i64 *%dst, i64 %a) {
; CHECK: f3:
; CHECK: agfi %r2, 524288
; CHECK: strvg %r3, 0(%r2)
; CHECK: br %r14
%ptr = getelementptr i64 *%dst, i64 65536
%swapped = call i64 @llvm.bswap.i64(i64 %a)
store i64 %swapped, i64 *%ptr
ret void
}
; Check the high end of the negative aligned STRVG range.
define void @f4(i64 *%dst, i64 %a) {
; CHECK: f4:
; CHECK: strvg %r3, -8(%r2)
; CHECK: br %r14
%ptr = getelementptr i64 *%dst, i64 -1
%swapped = call i64 @llvm.bswap.i64(i64 %a)
store i64 %swapped, i64 *%ptr
ret void
}
; Check the low end of the STRVG range.
define void @f5(i64 *%dst, i64 %a) {
; CHECK: f5:
; CHECK: strvg %r3, -524288(%r2)
; CHECK: br %r14
%ptr = getelementptr i64 *%dst, i64 -65536
%swapped = call i64 @llvm.bswap.i64(i64 %a)
store i64 %swapped, i64 *%ptr
ret void
}
; Check the next doubleword down, which needs separate address logic.
; Other sequences besides this one would be OK.
define void @f6(i64 *%dst, i64 %a) {
; CHECK: f6:
; CHECK: agfi %r2, -524296
; CHECK: strvg %r3, 0(%r2)
; CHECK: br %r14
%ptr = getelementptr i64 *%dst, i64 -65537
%swapped = call i64 @llvm.bswap.i64(i64 %a)
store i64 %swapped, i64 *%ptr
ret void
}
; Check that STRVG allows an index.
define void @f7(i64 %src, i64 %index, i64 %a) {
; CHECK: f7:
; CHECK: strvg %r4, 524287({{%r3,%r2|%r2,%r3}})
; CHECK: br %r14
%add1 = add i64 %src, %index
%add2 = add i64 %add1, 524287
%ptr = inttoptr i64 %add2 to i64 *
%swapped = call i64 @llvm.bswap.i64(i64 %a)
store i64 %swapped, i64 *%ptr
ret void
}
; Check that volatile stores do not use STRVG, which might access the
; storage multple times.
define void @f8(i64 *%dst, i64 %a) {
; CHECK: f8:
; CHECK: lrvgr [[REG:%r[0-5]]], %r3
; CHECK: stg [[REG]], 0(%r2)
; CHECK: br %r14
%swapped = call i64 @llvm.bswap.i64(i64 %a)
store volatile i64 %swapped, i64 *%dst
ret void
}