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[X86] Add test case for future MULFIX DAG combine folds. NFC
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Add some test cases displaying the lack of DAG combine
folds for SMULFIX/UMULFIX/SMULFIXSAT when either
multiplicand is undef or zero.

It seems like widening vector legalization for X86 can
introduce fixed point multiplication of undef values.
So that is one way that such operations could appear
during ISel.

Multiplication with zero is probably more unlikely, and
could potentially be handled by InstCombine. But I do
not think it would hurt to do such folds in DAGCombiner.

This patch only adds the test case. The folds will be
added in a follow up patch.

llvm-svn: 369102
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@bjope
bjope committed Aug 16, 2019
1 parent 8c2c5f5 commit 6a75061
Showing 1 changed file with 206 additions and 0 deletions.
206 changes: 206 additions & 0 deletions llvm/test/CodeGen/X86/mulfix_combine.ll
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; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc < %s -mtriple=x86_64-linux -o - | FileCheck %s

declare i32 @llvm.smul.fix.i32(i32, i32, i32 immarg)
declare i32 @llvm.umul.fix.i32(i32, i32, i32 immarg)
declare i32 @llvm.smul.fix.sat.i32(i32, i32, i32 immarg)

declare <4 x i32> @llvm.smul.fix.v4i32(<4 x i32>, <4 x i32>, i32 immarg)
declare <4 x i32> @llvm.umul.fix.v4i32(<4 x i32>, <4 x i32>, i32 immarg)
declare <4 x i32> @llvm.smul.fix.sat.v4i32(<4 x i32>, <4 x i32>, i32 immarg)

define i32 @smulfix_undef(i32 %y) nounwind {
; CHECK-LABEL: smulfix_undef:
; CHECK: # %bb.0:
; CHECK-NEXT: xorl %eax, %eax
; CHECK-NEXT: shrdl $2, %eax, %eax
; CHECK-NEXT: retq
%tmp = call i32 @llvm.smul.fix.i32(i32 undef, i32 %y, i32 2)
ret i32 %tmp
}

define i32 @smulfix_zero(i32 %y) nounwind {
; CHECK-LABEL: smulfix_zero:
; CHECK: # %bb.0:
; CHECK-NEXT: xorl %eax, %eax
; CHECK-NEXT: shrdl $2, %eax, %eax
; CHECK-NEXT: retq
%tmp = call i32 @llvm.smul.fix.i32(i32 0, i32 %y, i32 2)
ret i32 %tmp
}

define i32 @umulfix_undef(i32 %y) nounwind {
; CHECK-LABEL: umulfix_undef:
; CHECK: # %bb.0:
; CHECK-NEXT: xorl %eax, %eax
; CHECK-NEXT: shrdl $2, %eax, %eax
; CHECK-NEXT: retq
%tmp = call i32 @llvm.umul.fix.i32(i32 undef, i32 %y, i32 2)
ret i32 %tmp
}

define i32 @umulfix_zero(i32 %y) nounwind {
; CHECK-LABEL: umulfix_zero:
; CHECK: # %bb.0:
; CHECK-NEXT: xorl %eax, %eax
; CHECK-NEXT: shrdl $2, %eax, %eax
; CHECK-NEXT: retq
%tmp = call i32 @llvm.umul.fix.i32(i32 0, i32 %y, i32 2)
ret i32 %tmp
}

define i32 @smulfixsat_undef(i32 %y) nounwind {
; CHECK-LABEL: smulfixsat_undef:
; CHECK: # %bb.0:
; CHECK-NEXT: xorl %eax, %eax
; CHECK-NEXT: shrdl $2, %eax, %eax
; CHECK-NEXT: movl $1, %ecx
; CHECK-NEXT: negl %ecx
; CHECK-NEXT: movl $2147483647, %ecx # imm = 0x7FFFFFFF
; CHECK-NEXT: cmovlel %eax, %ecx
; CHECK-NEXT: movl $-2, %eax
; CHECK-NEXT: negl %eax
; CHECK-NEXT: movl $-2147483648, %eax # imm = 0x80000000
; CHECK-NEXT: cmovgel %ecx, %eax
; CHECK-NEXT: retq
%tmp = call i32 @llvm.smul.fix.sat.i32(i32 undef, i32 %y, i32 2)
ret i32 %tmp
}

define i32 @smulfixsat_zero(i32 %y) nounwind {
; CHECK-LABEL: smulfixsat_zero:
; CHECK: # %bb.0:
; CHECK-NEXT: xorl %eax, %eax
; CHECK-NEXT: shrdl $2, %eax, %eax
; CHECK-NEXT: movl $1, %ecx
; CHECK-NEXT: negl %ecx
; CHECK-NEXT: movl $2147483647, %ecx # imm = 0x7FFFFFFF
; CHECK-NEXT: cmovlel %eax, %ecx
; CHECK-NEXT: movl $-2, %eax
; CHECK-NEXT: negl %eax
; CHECK-NEXT: movl $-2147483648, %eax # imm = 0x80000000
; CHECK-NEXT: cmovgel %ecx, %eax
; CHECK-NEXT: retq
%tmp = call i32 @llvm.smul.fix.sat.i32(i32 0, i32 %y, i32 2)
ret i32 %tmp
}

define <4 x i32> @vec_smulfix_undef(<4 x i32> %y) nounwind {
; CHECK-LABEL: vec_smulfix_undef:
; CHECK: # %bb.0:
; CHECK-NEXT: pshufd {{.*#+}} xmm1 = xmm0[1,1,3,3]
; CHECK-NEXT: pxor %xmm2, %xmm2
; CHECK-NEXT: pcmpgtd %xmm0, %xmm2
; CHECK-NEXT: pand %xmm0, %xmm2
; CHECK-NEXT: pmuludq %xmm0, %xmm0
; CHECK-NEXT: pshufd {{.*#+}} xmm0 = xmm0[1,3,2,3]
; CHECK-NEXT: pmuludq %xmm0, %xmm1
; CHECK-NEXT: pshufd {{.*#+}} xmm1 = xmm1[1,3,2,3]
; CHECK-NEXT: punpckldq {{.*#+}} xmm0 = xmm0[0],xmm1[0],xmm0[1],xmm1[1]
; CHECK-NEXT: psubd %xmm2, %xmm0
; CHECK-NEXT: pslld $30, %xmm0
; CHECK-NEXT: retq
%tmp = call <4 x i32> @llvm.smul.fix.v4i32(<4 x i32> undef, <4 x i32> %y, i32 2)
ret <4 x i32> %tmp
}

define <4 x i32> @vec_smulfix_zero(<4 x i32> %y) nounwind {
; CHECK-LABEL: vec_smulfix_zero:
; CHECK: # %bb.0:
; CHECK-NEXT: pxor %xmm1, %xmm1
; CHECK-NEXT: pxor %xmm2, %xmm2
; CHECK-NEXT: pmuludq %xmm0, %xmm2
; CHECK-NEXT: pshufd {{.*#+}} xmm3 = xmm2[0,2,2,3]
; CHECK-NEXT: pshufd {{.*#+}} xmm4 = xmm0[1,1,3,3]
; CHECK-NEXT: pmuludq %xmm1, %xmm4
; CHECK-NEXT: pshufd {{.*#+}} xmm0 = xmm4[0,2,2,3]
; CHECK-NEXT: punpckldq {{.*#+}} xmm3 = xmm3[0],xmm0[0],xmm3[1],xmm0[1]
; CHECK-NEXT: psrld $2, %xmm3
; CHECK-NEXT: pshufd {{.*#+}} xmm0 = xmm2[1,3,2,3]
; CHECK-NEXT: pshufd {{.*#+}} xmm1 = xmm4[1,3,2,3]
; CHECK-NEXT: punpckldq {{.*#+}} xmm0 = xmm0[0],xmm1[0],xmm0[1],xmm1[1]
; CHECK-NEXT: pslld $30, %xmm0
; CHECK-NEXT: por %xmm3, %xmm0
; CHECK-NEXT: retq
%tmp = call <4 x i32> @llvm.smul.fix.v4i32(<4 x i32> <i32 0, i32 0, i32 0, i32 0>, <4 x i32> %y, i32 2)
ret <4 x i32> %tmp
}

define <4 x i32> @vec_umulfix_undef(<4 x i32> %y) nounwind {
; CHECK-LABEL: vec_umulfix_undef:
; CHECK: # %bb.0:
; CHECK-NEXT: pshufd {{.*#+}} xmm1 = xmm0[1,1,3,3]
; CHECK-NEXT: pmuludq %xmm0, %xmm0
; CHECK-NEXT: pshufd {{.*#+}} xmm0 = xmm0[1,3,2,3]
; CHECK-NEXT: pmuludq %xmm0, %xmm1
; CHECK-NEXT: pshufd {{.*#+}} xmm1 = xmm1[1,3,2,3]
; CHECK-NEXT: punpckldq {{.*#+}} xmm0 = xmm0[0],xmm1[0],xmm0[1],xmm1[1]
; CHECK-NEXT: pslld $30, %xmm0
; CHECK-NEXT: retq
%tmp = call <4 x i32> @llvm.umul.fix.v4i32(<4 x i32> undef, <4 x i32> %y, i32 2)
ret <4 x i32> %tmp
}

define <4 x i32> @vec_umulfix_zero(<4 x i32> %y) nounwind {
; CHECK-LABEL: vec_umulfix_zero:
; CHECK: # %bb.0:
; CHECK-NEXT: pxor %xmm1, %xmm1
; CHECK-NEXT: pxor %xmm2, %xmm2
; CHECK-NEXT: pmuludq %xmm0, %xmm2
; CHECK-NEXT: pshufd {{.*#+}} xmm3 = xmm2[0,2,2,3]
; CHECK-NEXT: pshufd {{.*#+}} xmm4 = xmm0[1,1,3,3]
; CHECK-NEXT: pmuludq %xmm1, %xmm4
; CHECK-NEXT: pshufd {{.*#+}} xmm0 = xmm4[0,2,2,3]
; CHECK-NEXT: punpckldq {{.*#+}} xmm3 = xmm3[0],xmm0[0],xmm3[1],xmm0[1]
; CHECK-NEXT: psrld $2, %xmm3
; CHECK-NEXT: pshufd {{.*#+}} xmm0 = xmm2[1,3,2,3]
; CHECK-NEXT: pshufd {{.*#+}} xmm1 = xmm4[1,3,2,3]
; CHECK-NEXT: punpckldq {{.*#+}} xmm0 = xmm0[0],xmm1[0],xmm0[1],xmm1[1]
; CHECK-NEXT: pslld $30, %xmm0
; CHECK-NEXT: por %xmm3, %xmm0
; CHECK-NEXT: retq
%tmp = call <4 x i32> @llvm.umul.fix.v4i32(<4 x i32> <i32 0, i32 0, i32 0, i32 0>, <4 x i32> %y, i32 2)
ret <4 x i32> %tmp
}

define <4 x i32> @vec_smulfixsat_undef(<4 x i32> %y) nounwind {
; CHECK-LABEL: vec_smulfixsat_undef:
; CHECK: # %bb.0:
; CHECK-NEXT: xorl %eax, %eax
; CHECK-NEXT: shrdl $2, %eax, %eax
; CHECK-NEXT: movl $1, %ecx
; CHECK-NEXT: negl %ecx
; CHECK-NEXT: movl $2147483647, %ecx # imm = 0x7FFFFFFF
; CHECK-NEXT: cmovlel %eax, %ecx
; CHECK-NEXT: movl $-2, %eax
; CHECK-NEXT: negl %eax
; CHECK-NEXT: movl $-2147483648, %eax # imm = 0x80000000
; CHECK-NEXT: cmovgel %ecx, %eax
; CHECK-NEXT: movd %eax, %xmm0
; CHECK-NEXT: punpckldq {{.*#+}} xmm0 = xmm0[0,0,1,1]
; CHECK-NEXT: punpcklqdq {{.*#+}} xmm0 = xmm0[0,0]
; CHECK-NEXT: retq
%tmp = call <4 x i32> @llvm.smul.fix.sat.v4i32(<4 x i32> undef, <4 x i32> %y, i32 2)
ret <4 x i32> %tmp
}

define <4 x i32> @vec_smulfixsat_zero(<4 x i32> %y) nounwind {
; CHECK-LABEL: vec_smulfixsat_zero:
; CHECK: # %bb.0:
; CHECK-NEXT: xorl %eax, %eax
; CHECK-NEXT: shrdl $2, %eax, %eax
; CHECK-NEXT: movl $1, %ecx
; CHECK-NEXT: negl %ecx
; CHECK-NEXT: movl $2147483647, %ecx # imm = 0x7FFFFFFF
; CHECK-NEXT: cmovlel %eax, %ecx
; CHECK-NEXT: movl $-2, %eax
; CHECK-NEXT: negl %eax
; CHECK-NEXT: movl $-2147483648, %eax # imm = 0x80000000
; CHECK-NEXT: cmovgel %ecx, %eax
; CHECK-NEXT: movd %eax, %xmm0
; CHECK-NEXT: punpckldq {{.*#+}} xmm0 = xmm0[0,0,1,1]
; CHECK-NEXT: punpcklqdq {{.*#+}} xmm0 = xmm0[0,0]
; CHECK-NEXT: retq
%tmp = call <4 x i32> @llvm.smul.fix.sat.v4i32(<4 x i32> <i32 0, i32 0, i32 0, i32 0>, <4 x i32> %y, i32 2)
ret <4 x i32> %tmp
}

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