llvm-6502/test/CodeGen/ARM/neon_cmp.ll
Arnold Schwaighofer c46e2df74c DAGCombiner: Fold pointless truncate, bitcast, buildvector series
(2xi32) (truncate ((2xi64) bitcast (buildvector i32 a, i32 x, i32 b, i32 y)))
can be folded into a (2xi32) (buildvector i32 a, i32 b).

Such a DAG would cause uneccessary vdup instructions followed by vmovn
instructions.

We generate this code on ARM NEON for a setcc olt, 2xf64, 2xf64. For example, in
the vectorized version of the code below.

double A[N];
double B[N];

void test_double_compare_to_double() {
  int i;
  for(i=0;i<N;i++)
    A[i] = (double)(A[i] < B[i]);
}

radar://13191881

Fixes bug 15283.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175670 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-20 21:33:32 +00:00

16 lines
501 B
LLVM

; RUN: llc < %s -march=arm -mcpu=cortex-a9 | FileCheck %s
; bug 15283
; radar://13191881
; CHECK: vfcmp
define void @vfcmp(<2 x double>* %a, <2 x double>* %b) {
%wide.load = load <2 x double>* %a, align 4
%wide.load2 = load <2 x double>* %b, align 4
; CHECK-NOT: vdup.32
; CHECK-NOT: vmovn.i64
%v1 = fcmp olt <2 x double> %wide.load, %wide.load2
%v2 = zext <2 x i1> %v1 to <2 x i32>
%v3 = sitofp <2 x i32> %v2 to <2 x double>
store <2 x double> %v3, <2 x double>* %b, align 4
ret void
}