llvm/test/CodeGen/AArch64/free-zext.ll
Geoff Berry 2d2aadfa70 [CodeGenPrepare] Create more extloads and fewer ands
Summary:
Add and instructions immediately after loads that only have their low
bits used, assuming that the (and (load x) c) will be matched as a
extload and the ands/truncs fed by the extload will be removed by isel.

Reviewers: mcrosier, qcolombet, ab

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D14584

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253722 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-20 22:34:39 +00:00

72 lines
2.2 KiB
LLVM

; RUN: llc -verify-machineinstrs -o - %s -mtriple=arm64-apple-ios7.0 | FileCheck %s
define i64 @test_free_zext(i8* %a, i16* %b) {
; CHECK-LABEL: test_free_zext:
; CHECK-DAG: ldrb w[[A:[0-9]+]], [x0]
; CHECK: ldrh w[[B:[0-9]+]], [x1]
; CHECK: add x0, x[[B]], x[[A]]
%1 = load i8, i8* %a, align 1
%conv = zext i8 %1 to i64
%2 = load i16, i16* %b, align 2
%conv1 = zext i16 %2 to i64
%add = add nsw i64 %conv1, %conv
ret i64 %add
}
define void @test_free_zext2(i32* %ptr, i32* %dst1, i64* %dst2) {
; CHECK-LABEL: test_free_zext2:
; CHECK: ldrh w[[A:[0-9]+]], [x0]
; CHECK-NOT: and x
; CHECK: str w[[A]], [x1]
; CHECK: str x[[A]], [x2]
%load = load i32, i32* %ptr, align 8
%load16 = and i32 %load, 65535
%load64 = zext i32 %load16 to i64
store i32 %load16, i32* %dst1, align 4
store i64 %load64, i64* %dst2, align 8
ret void
}
; Test for CodeGenPrepare::optimizeLoadExt(): simple case: two loads
; feeding a phi that zext's each loaded value.
define i32 @test_free_zext3(i32* %ptr, i32* %ptr2, i32* %dst, i32 %c) {
; CHECK-LABEL: test_free_zext3:
bb1:
; CHECK: ldrh [[REG:w[0-9]+]]
; CHECK-NOT: and {{w[0-9]+}}, [[REG]], #0xffff
%tmp1 = load i32, i32* %ptr, align 4
%cmp = icmp ne i32 %c, 0
br i1 %cmp, label %bb2, label %bb3
bb2:
; CHECK: ldrh [[REG2:w[0-9]+]]
; CHECK-NOT: and {{w[0-9]+}}, [[REG2]], #0xffff
%tmp2 = load i32, i32* %ptr2, align 4
br label %bb3
bb3:
%tmp3 = phi i32 [ %tmp1, %bb1 ], [ %tmp2, %bb2 ]
; CHECK-NOT: and {{w[0-9]+}}, {{w[0-9]+}}, #0xffff
%tmpand = and i32 %tmp3, 65535
ret i32 %tmpand
}
; Test for CodeGenPrepare::optimizeLoadExt(): check case of zext-able
; load feeding a phi in the same block.
define void @test_free_zext4(i32* %ptr, i32* %ptr2, i32* %dst) {
; CHECK-LABEL: test_free_zext4:
; CHECK: ldrh [[REG:w[0-9]+]]
; TODO: fix isel to remove final and XCHECK-NOT: and {{w[0-9]+}}, {{w[0-9]+}}, #0xffff
; CHECK: ldrh [[REG:w[0-9]+]]
bb1:
%load1 = load i32, i32* %ptr, align 4
br label %loop
loop:
%phi = phi i32 [ %load1, %bb1 ], [ %load2, %loop ]
%and = and i32 %phi, 65535
store i32 %and, i32* %dst, align 4
%load2 = load i32, i32* %ptr2, align 4
%cmp = icmp ne i32 %and, 0
br i1 %cmp, label %loop, label %end
end:
ret void
}