llvm-project/llvm/test/CodeGen/X86/stores-merging.ll

57 lines
2.3 KiB
LLVM

; RUN: llc < %s | FileCheck %s
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
%structTy = type { i8, i32, i32 }
@e = common global %structTy zeroinitializer, align 4
;; Ensure that MergeConsecutiveStores doesn't incorrectly reorder
;; store operations. The first test stores in increasing address
;; order, the second in decreasing -- but in both cases should have
;; the same result in memory in the end.
; CHECK-LABEL: redundant_stores_merging:
; CHECK: movabsq $528280977409, %rax
; CHECK: movq %rax, e+4(%rip)
; CHECK: movl $456, e+8(%rip)
define void @redundant_stores_merging() {
entry:
store i32 1, i32* getelementptr inbounds (%structTy, %structTy* @e, i64 0, i32 1), align 4
store i32 123, i32* getelementptr inbounds (%structTy, %structTy* @e, i64 0, i32 2), align 4
store i32 456, i32* getelementptr inbounds (%structTy, %structTy* @e, i64 0, i32 2), align 4
ret void
}
;; This variant tests PR25154.
; CHECK-LABEL: redundant_stores_merging_reverse:
; CHECK: movabsq $528280977409, %rax
; CHECK: movq %rax, e+4(%rip)
; CHECK: movl $456, e+8(%rip)
define void @redundant_stores_merging_reverse() {
entry:
store i32 123, i32* getelementptr inbounds (%structTy, %structTy* @e, i64 0, i32 2), align 4
store i32 456, i32* getelementptr inbounds (%structTy, %structTy* @e, i64 0, i32 2), align 4
store i32 1, i32* getelementptr inbounds (%structTy, %structTy* @e, i64 0, i32 1), align 4
ret void
}
@b = common global [8 x i8] zeroinitializer, align 2
;; The 2-byte store to offset 3 overlaps the 2-byte store to offset 2;
;; these must not be reordered in MergeConsecutiveStores such that the
;; store to 3 comes first (e.g. by merging the stores to 0 and 2 into
;; a movl, after the store to 3).
;; CHECK-LABEL: overlapping_stores_merging:
;; CHECK: movl $1, b(%rip)
;; CHECK: movw $2, b+3(%rip)
define void @overlapping_stores_merging() {
entry:
store i16 0, i16* bitcast (i8* getelementptr inbounds ([8 x i8], [8 x i8]* @b, i64 0, i64 2) to i16*), align 2
store i16 2, i16* bitcast (i8* getelementptr inbounds ([8 x i8], [8 x i8]* @b, i64 0, i64 3) to i16*), align 1
store i16 1, i16* bitcast (i8* getelementptr inbounds ([8 x i8], [8 x i8]* @b, i64 0, i64 0) to i16*), align 2
ret void
}