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llvm-project/llvm/test/CodeGen/PowerPC/splat-bug.ll

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Adding -verify-machineinstrs option to PowerPC tests Currently we have a number of tests that fail with -verify-machineinstrs. To detect this cases earlier we add the option to the testcases with the exception of tests that will currently fail with this option. PR 27456 keeps track of this failures. No code review, as discussed with Hal Finkel. llvm-svn: 277624
2016-08-04 02:17:35 +08:00
; RUN: llc -verify-machineinstrs -mcpu=ppc64 -O0 -fast-isel=false < %s | FileCheck %s
[PATCH] Correct type used for VADD_SPLAT optimization on PowerPC In PPCISelLowering.cpp: PPCTargetLowering::LowerBUILD_VECTOR(), there is an optimization for certain patterns to generate one or two vector splats followed by a vector add or subtract. This operation is represented by a VADD_SPLAT in the selection DAG. Prior to this patch, it was possible for the VADD_SPLAT to be assigned the wrong data type, causing incorrect code generation. This patch corrects the problem. Specifically, the code previously assigned the value type of the BUILD_VECTOR node to the newly generated VADD_SPLAT node. This is correct much of the time, but not always. The problem is that the call to isConstantSplat() may return a SplatBitSize that is not the same as the number of bits in the original element vector type. The correct type to assign is a vector type with the same element bit size as SplatBitSize. The included test case shows an example of this, where the BUILD_VECTOR node has a type of v16i8. The vector to be built is {0, 16, 0, 16, 0, 16, 0, 16, 0, 16, 0, 16, 0, 16, 0, 16}. isConstantSplat detects that we can generate a splat of 16 for type v8i16, which is the type we must assign to the VADD_SPLAT node. If we do not, we generate a vspltisb of 8 and a vaddubm, which generates the incorrect result {16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16}. The correct code generation is a vspltish of 8 and a vadduhm. This patch also corrected code generation for CodeGen/PowerPC/2008-07-10-SplatMiscompile.ll, which had been marked as an XFAIL, so we can remove the XFAIL from the test case. llvm-svn: 209662
2014-05-27 23:57:51 +08:00
; Checks for a previous bug where vspltisb/vaddubm were issued in place
; of vsplitsh/vadduhm.
target datalayout = "E-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v128:128:128-n32:64"
target triple = "powerpc64-unknown-linux-gnu"
@a = external global <16 x i8>
define void @foo() nounwind ssp {
; CHECK: foo:
store <16 x i8> <i8 0, i8 16, i8 0, i8 16, i8 0, i8 16, i8 0, i8 16, i8 0, i8 16, i8 0, i8 16, i8 0, i8 16, i8 0, i8 16>, <16 x i8>* @a
; CHECK: vspltish [[REG:[0-9]+]], 8
; CHECK: vadduhm {{[0-9]+}}, [[REG]], [[REG]]
ret void
}