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llvm-mirror/test/CodeGen/SystemZ/alloca-02.ll
Richard Sandiford de9eba2208 [SystemZ] Prefer LHI;ST... over LAY;MV...
If we had a store of an integer to memory, and the integer and store size
were suitable for a form of MV..., we used MV... no matter what.  We could
then have sequences like:

    lay %r2, 0(%r3,%r4)
    mvi 0(%r2), 4

In these cases it seems better to force the constant into a register
and use a normal store:

    lhi %r2, 4
    stc %r2, 0(%r3, %r4)

since %r2 is more likely to be hoisted and is easier to rematerialize.

llvm-svn: 189098
2013-08-23 11:18:53 +00:00

53 lines
1.7 KiB
LLVM

; Make sure that the alloca offset isn't lost when the alloca result is
; used directly in a load or store. There must always be an LA or LAY.
;
; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s -check-prefix=CHECK-A
; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s -check-prefix=CHECK-B
; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s -check-prefix=CHECK-C
; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s -check-prefix=CHECK-D
declare i64 @bar(i8 *%a)
define i64 @f1(i64 %length, i64 %index) {
; CHECK-A-LABEL: f1:
; CHECK-A: lgr %r15, [[ADDR:%r[1-5]]]
; CHECK-A: la %r2, 160([[ADDR]])
; CHECK-A: mvi 0(%r2), 0
;
; CHECK-B-LABEL: f1:
; CHECK-B: lgr %r15, [[ADDR:%r[1-5]]]
; CHECK-B: la %r2, 160([[ADDR]])
; CHECK-B: mvi 4095(%r2), 1
;
; CHECK-C-LABEL: f1:
; CHECK-C: lgr %r15, [[ADDR:%r[1-5]]]
; CHECK-C-DAG: la %r2, 160([[ADDR]])
; CHECK-C-DAG: lhi [[TMP:%r[0-5]]], 2
; CHECK-C: stc [[TMP]], 0({{%r3,%r2|%r2,%r3}})
;
; CHECK-D-LABEL: f1:
; CHECK-D: lgr %r15, [[ADDR:%r[1-5]]]
; CHECK-D-DAG: la %r2, 160([[ADDR]])
; CHECK-D-DAG: lhi [[TMP:%r[0-5]]], 3
; CHECK-D: stc [[TMP]], 4095({{%r3,%r2|%r2,%r3}})
;
; CHECK-E-LABEL: f1:
; CHECK-E: lgr %r15, [[ADDR:%r[1-5]]]
; CHECK-E-DAG: la %r2, 160([[ADDR]])
; CHECK-E-DAG: lhi [[TMP:%r[0-5]]], 4
; CHECK-E: stcy [[TMP]], 4096({{%r3,%r2|%r2,%r3}})
%a = alloca i8, i64 %length
store volatile i8 0, i8 *%a
%b = getelementptr i8 *%a, i64 4095
store volatile i8 1, i8 *%b
%c = getelementptr i8 *%a, i64 %index
store volatile i8 2, i8 *%c
%d = getelementptr i8 *%c, i64 4095
store volatile i8 3, i8 *%d
%e = getelementptr i8 *%d, i64 1
store volatile i8 4, i8 *%e
%count = call i64 @bar(i8 *%a)
%res = add i64 %count, 1
ret i64 %res
}