llvm-6502/test/CodeGen/AArch64/aarch64-gep-opt.ll
James Molloy 89cc8dd3b8 [AArch64] Disable complex GEP optimization by default.
Enough concerns were raised that this optimization is pessimising some code patterns.

The obvious fix, to add a Reassociate run afterwards, causes even more pessimisation in some cases due to fewer complex addressing modes being matched. As there isn't a trivial fix for this, backing this out by default until someone gets a chance to fix the addressing mode matcher.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235491 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-22 09:11:38 +00:00

164 lines
6.3 KiB
LLVM

; RUN: llc -O3 -aarch64-gep-opt=true -verify-machineinstrs %s -o - | FileCheck %s
; RUN: llc -O3 -aarch64-gep-opt=true -print-after=codegenprepare -mcpu=cyclone < %s >%t 2>&1 && FileCheck --check-prefix=CHECK-NoAA <%t %s
; RUN: llc -O3 -aarch64-gep-opt=true -print-after=codegenprepare -mcpu=cortex-a53 < %s >%t 2>&1 && FileCheck --check-prefix=CHECK-UseAA <%t %s
target datalayout = "e-m:e-i64:64-i128:128-n32:64-S128"
target triple = "aarch64-linux-gnueabi"
; Following test cases test enabling SeparateConstOffsetFromGEP pass in AArch64
; backend. If useAA() returns true, it will lower a GEP with multiple indices
; into GEPs with a single index, otherwise it will lower it into a
; "ptrtoint+arithmetics+inttoptr" form.
%struct = type { i32, i32, i32, i32, [20 x i32] }
; Check that when two complex GEPs are used in two basic blocks, LLVM can
; elimilate the common subexpression for the second use.
define void @test_GEP_CSE([240 x %struct]* %string, i32* %adj, i32 %lib, i64 %idxprom) {
%liberties = getelementptr [240 x %struct], [240 x %struct]* %string, i64 1, i64 %idxprom, i32 3
%1 = load i32, i32* %liberties, align 4
%cmp = icmp eq i32 %1, %lib
br i1 %cmp, label %if.then, label %if.end
if.then: ; preds = %entry
%origin = getelementptr [240 x %struct], [240 x %struct]* %string, i64 1, i64 %idxprom, i32 2
%2 = load i32, i32* %origin, align 4
store i32 %2, i32* %adj, align 4
br label %if.end
if.end: ; preds = %if.then, %entry
ret void
}
; CHECK-LABEL: test_GEP_CSE:
; CHECK: madd
; CHECK: ldr
; CHECK-NOT: madd
; CHECK:ldr
; CHECK-NoAA-LABEL: @test_GEP_CSE(
; CHECK-NoAA: [[PTR0:%[a-zA-Z0-9]+]] = ptrtoint [240 x %struct]* %string to i64
; CHECK-NoAA: [[PTR1:%[a-zA-Z0-9]+]] = mul i64 %idxprom, 96
; CHECK-NoAA: [[PTR2:%[a-zA-Z0-9]+]] = add i64 [[PTR0]], [[PTR1]]
; CHECK-NoAA: add i64 [[PTR2]], 23052
; CHECK-NoAA: inttoptr
; CHECK-NoAA: if.then:
; CHECK-NoAA-NOT: ptrtoint
; CHECK-NoAA-NOT: mul
; CHECK-NoAA: add i64 [[PTR2]], 23048
; CHECK-NoAA: inttoptr
; CHECK-UseAA-LABEL: @test_GEP_CSE(
; CHECK-UseAA: [[PTR0:%[a-zA-Z0-9]+]] = bitcast [240 x %struct]* %string to i8*
; CHECK-UseAA: [[IDX:%[a-zA-Z0-9]+]] = mul i64 %idxprom, 96
; CHECK-UseAA: [[PTR1:%[a-zA-Z0-9]+]] = getelementptr i8, i8* [[PTR0]], i64 [[IDX]]
; CHECK-UseAA: getelementptr i8, i8* [[PTR1]], i64 23052
; CHECK-UseAA: bitcast
; CHECK-UseAA: if.then:
; CHECK-UseAA: getelementptr i8, i8* [[PTR1]], i64 23048
; CHECK-UseAA: bitcast
%class.my = type { i32, [128 x i32], i32, [256 x %struct.pt]}
%struct.pt = type { %struct.point*, i32, i32 }
%struct.point = type { i32, i32 }
; Check when a GEP is used across two basic block, LLVM can sink the address
; calculation and code gen can generate a better addressing mode for the second
; use.
define void @test_GEP_across_BB(%class.my* %this, i64 %idx) {
%1 = getelementptr %class.my, %class.my* %this, i64 0, i32 3, i64 %idx, i32 1
%2 = load i32, i32* %1, align 4
%3 = getelementptr %class.my, %class.my* %this, i64 0, i32 3, i64 %idx, i32 2
%4 = load i32, i32* %3, align 4
%5 = icmp eq i32 %2, %4
br i1 %5, label %if.true, label %exit
if.true:
%6 = shl i32 %4, 1
store i32 %6, i32* %3, align 4
br label %exit
exit:
%7 = add nsw i32 %4, 1
store i32 %7, i32* %1, align 4
ret void
}
; CHECK-LABEL: test_GEP_across_BB:
; CHECK: ldr {{w[0-9]+}}, [{{x[0-9]+}}, #528]
; CHECK: ldr {{w[0-9]+}}, [{{x[0-9]+}}, #532]
; CHECK-NOT: add
; CHECK: str {{w[0-9]+}}, [{{x[0-9]+}}, #532]
; CHECK: str {{w[0-9]+}}, [{{x[0-9]+}}, #528]
; CHECK-NoAA-LABEL: test_GEP_across_BB(
; CHECK-NoAA: add i64 [[TMP:%[a-zA-Z0-9]+]], 528
; CHECK-NoAA: add i64 [[TMP]], 532
; CHECK-NoAA: if.true:
; CHECK-NoAA: {{%sunk[a-zA-Z0-9]+}} = add i64 [[TMP]], 532
; CHECK-NoAA: exit:
; CHECK-NoAA: {{%sunk[a-zA-Z0-9]+}} = add i64 [[TMP]], 528
; CHECK-UseAA-LABEL: test_GEP_across_BB(
; CHECK-UseAA: [[PTR0:%[a-zA-Z0-9]+]] = getelementptr
; CHECK-UseAA: getelementptr i8, i8* [[PTR0]], i64 528
; CHECK-UseAA: getelementptr i8, i8* [[PTR0]], i64 532
; CHECK-UseAA: if.true:
; CHECK-UseAA: {{%sunk[a-zA-Z0-9]+}} = getelementptr i8, i8* [[PTR0]], i64 532
; CHECK-UseAA: exit:
; CHECK-UseAA: {{%sunk[a-zA-Z0-9]+}} = getelementptr i8, i8* [[PTR0]], i64 528
%struct.S = type { float, double }
@struct_array = global [1024 x %struct.S] zeroinitializer, align 16
; The following two test cases check we can extract constant from indices of
; struct type.
; The constant offsets are from indices "i64 %idxprom" and "i32 1". As the
; alloca size of %struct.S is 16, and "i32 1" is the 2rd element whose field
; offset is 8, the total constant offset is (5 * 16 + 8) = 88.
define double* @test-struct_1(i32 %i) {
entry:
%add = add nsw i32 %i, 5
%idxprom = sext i32 %add to i64
%p = getelementptr [1024 x %struct.S], [1024 x %struct.S]* @struct_array, i64 0, i64 %idxprom, i32 1
ret double* %p
}
; CHECK-NoAA-LABEL: @test-struct_1(
; CHECK-NoAA-NOT: getelementptr
; CHECK-NoAA: add i64 %{{[a-zA-Z0-9]+}}, 88
; CHECK-UseAA-LABEL: @test-struct_1(
; CHECK-UseAA: getelementptr i8, i8* %{{[a-zA-Z0-9]+}}, i64 88
%struct3 = type { i64, i32 }
%struct2 = type { %struct3, i32 }
%struct1 = type { i64, %struct2 }
%struct0 = type { i32, i32, i64*, [100 x %struct1] }
; The constant offsets are from indices "i32 3", "i64 %arrayidx" and "i32 1".
; "i32 3" is the 4th element whose field offset is 16. The alloca size of
; %struct1 is 32. "i32 1" is the 2rd element whose field offset is 8. So the
; total constant offset is 16 + (-2 * 32) + 8 = -40
define %struct2* @test-struct_2(%struct0* %ptr, i64 %idx) {
entry:
%arrayidx = add nsw i64 %idx, -2
%ptr2 = getelementptr %struct0, %struct0* %ptr, i64 0, i32 3, i64 %arrayidx, i32 1
ret %struct2* %ptr2
}
; CHECK-NoAA-LABEL: @test-struct_2(
; CHECK-NoAA-NOT: = getelementptr
; CHECK-NoAA: add i64 %{{[a-zA-Z0-9]+}}, -40
; CHECK-UseAA-LABEL: @test-struct_2(
; CHECK-UseAA: getelementptr i8, i8* %{{[a-zA-Z0-9]+}}, i64 -40
; Test that when a index is added from two constant, SeparateConstOffsetFromGEP
; pass does not generate incorrect result.
define void @test_const_add([3 x i32]* %in) {
%inc = add nsw i32 2, 1
%idxprom = sext i32 %inc to i64
%arrayidx = getelementptr [3 x i32], [3 x i32]* %in, i64 %idxprom, i64 2
store i32 0, i32* %arrayidx, align 4
ret void
}
; CHECK-LABEL: test_const_add:
; CHECK: str wzr, [x0, #44]