[X86] Add target combine rules for horizontal add/sub.

This patch adds new target specific combine rules to identify horizontal
add/sub idioms from BUILD_VECTOR dag nodes.

This patch also teaches the DAGCombiner how to canonicalize sequences of
insert_vector_elt dag nodes according to the following rule:

  (insert_vector_elt (insert_vector_elt A, I0), I1) ->
    (insert_vecto_elt (insert_vector_elt A, I1), I0)

This new canonicalization rule only triggers if the inner insert_vector
dag node has exactly one use; also, both indices must be known constants,
and I1 < I0.
This last rule made it possible to write a simpler algorithm to identify
horizontal add/sub patterns because now we don't have to worry about the
ordering of insert_vector_elt dag nodes.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210477 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 376 insertions, 0 deletions

diff --git a/test/CodeGen/X86/haddsub-2.ll b/test/CodeGen/X86/haddsub-2.ll
new file mode 100644
index 0000000000..534d56a273
--- /dev/null
+++ b/test/CodeGen/X86/haddsub-2.ll
@@ -0,0 +1,376 @@
+; RUN: llc < %s -march=x86-64 -mattr=+sse2,+sse3 | FileCheck %s -check-prefix=CHECK -check-prefix=SSE3
+; RUN: llc < %s -march=x86-64 -mattr=+sse2,+sse3,+ssse3 | FileCheck %s -check-prefix=CHECK -check-prefix=SSSE3
+; RUN: llc < %s -march=x86-64 -mcpu=corei7-avx | FileCheck %s -check-prefix=CHECK -check-prefix=AVX
+; RUN: llc < %s -march=x86-64 -mcpu=core-avx2 | FileCheck %s -check-prefix=CHECK -check-prefix=AVX2
+
+
+
+define <4 x float> @hadd_ps_test1(<4 x float> %A, <4 x float> %B) {
+  %vecext = extractelement <4 x float> %A, i32 0
+  %vecext1 = extractelement <4 x float> %A, i32 1
+  %add = fadd float %vecext, %vecext1
+  %vecinit = insertelement <4 x float> undef, float %add, i32 0
+  %vecext2 = extractelement <4 x float> %A, i32 2
+  %vecext3 = extractelement <4 x float> %A, i32 3
+  %add4 = fadd float %vecext2, %vecext3
+  %vecinit5 = insertelement <4 x float> %vecinit, float %add4, i32 1
+  %vecext6 = extractelement <4 x float> %B, i32 0
+  %vecext7 = extractelement <4 x float> %B, i32 1
+  %add8 = fadd float %vecext6, %vecext7
+  %vecinit9 = insertelement <4 x float> %vecinit5, float %add8, i32 2
+  %vecext10 = extractelement <4 x float> %B, i32 2
+  %vecext11 = extractelement <4 x float> %B, i32 3
+  %add12 = fadd float %vecext10, %vecext11
+  %vecinit13 = insertelement <4 x float> %vecinit9, float %add12, i32 3
+  ret <4 x float> %vecinit13
+}
+; CHECK-LABEL: hadd_ps_test1
+; CHECK: haddps
+; CHECK-NEXT: ret
+
+
+define <4 x float> @hadd_ps_test2(<4 x float> %A, <4 x float> %B) {
+  %vecext = extractelement <4 x float> %A, i32 2
+  %vecext1 = extractelement <4 x float> %A, i32 3
+  %add = fadd float %vecext, %vecext1
+  %vecinit = insertelement <4 x float> undef, float %add, i32 1
+  %vecext2 = extractelement <4 x float> %A, i32 0
+  %vecext3 = extractelement <4 x float> %A, i32 1
+  %add4 = fadd float %vecext2, %vecext3
+  %vecinit5 = insertelement <4 x float> %vecinit, float %add4, i32 0
+  %vecext6 = extractelement <4 x float> %B, i32 2
+  %vecext7 = extractelement <4 x float> %B, i32 3
+  %add8 = fadd float %vecext6, %vecext7
+  %vecinit9 = insertelement <4 x float> %vecinit5, float %add8, i32 3
+  %vecext10 = extractelement <4 x float> %B, i32 0
+  %vecext11 = extractelement <4 x float> %B, i32 1
+  %add12 = fadd float %vecext10, %vecext11
+  %vecinit13 = insertelement <4 x float> %vecinit9, float %add12, i32 2
+  ret <4 x float> %vecinit13
+}
+; CHECK-LABEL: hadd_ps_test2
+; CHECK: haddps
+; CHECK-NEXT: ret
+
+
+define <4 x float> @hsub_ps_test1(<4 x float> %A, <4 x float> %B) {
+  %vecext = extractelement <4 x float> %A, i32 0
+  %vecext1 = extractelement <4 x float> %A, i32 1
+  %sub = fsub float %vecext, %vecext1
+  %vecinit = insertelement <4 x float> undef, float %sub, i32 0
+  %vecext2 = extractelement <4 x float> %A, i32 2
+  %vecext3 = extractelement <4 x float> %A, i32 3
+  %sub4 = fsub float %vecext2, %vecext3
+  %vecinit5 = insertelement <4 x float> %vecinit, float %sub4, i32 1
+  %vecext6 = extractelement <4 x float> %B, i32 0
+  %vecext7 = extractelement <4 x float> %B, i32 1
+  %sub8 = fsub float %vecext6, %vecext7
+  %vecinit9 = insertelement <4 x float> %vecinit5, float %sub8, i32 2
+  %vecext10 = extractelement <4 x float> %B, i32 2
+  %vecext11 = extractelement <4 x float> %B, i32 3
+  %sub12 = fsub float %vecext10, %vecext11
+  %vecinit13 = insertelement <4 x float> %vecinit9, float %sub12, i32 3
+  ret <4 x float> %vecinit13
+}
+; CHECK-LABEL: hsub_ps_test1
+; CHECK: hsubps
+; CHECK-NEXT: ret
+
+
+define <4 x float> @hsub_ps_test2(<4 x float> %A, <4 x float> %B) {
+  %vecext = extractelement <4 x float> %A, i32 2
+  %vecext1 = extractelement <4 x float> %A, i32 3
+  %sub = fsub float %vecext, %vecext1
+  %vecinit = insertelement <4 x float> undef, float %sub, i32 1
+  %vecext2 = extractelement <4 x float> %A, i32 0
+  %vecext3 = extractelement <4 x float> %A, i32 1
+  %sub4 = fsub float %vecext2, %vecext3
+  %vecinit5 = insertelement <4 x float> %vecinit, float %sub4, i32 0
+  %vecext6 = extractelement <4 x float> %B, i32 3
+  %vecext7 = extractelement <4 x float> %B, i32 2
+  %sub8 = fsub float %vecext6, %vecext7
+  %vecinit9 = insertelement <4 x float> %vecinit5, float %sub8, i32 3
+  %vecext10 = extractelement <4 x float> %B, i32 1
+  %vecext11 = extractelement <4 x float> %B, i32 0
+  %sub12 = fsub float %vecext10, %vecext11
+  %vecinit13 = insertelement <4 x float> %vecinit9, float %sub12, i32 2
+  ret <4 x float> %vecinit13
+}
+; CHECK-LABEL: hsub_ps_test2
+; CHECK: hsubps
+; CHECK-NEXT: ret
+
+
+define <4 x i32> @phadd_d_test1(<4 x i32> %A, <4 x i32> %B) {
+  %vecext = extractelement <4 x i32> %A, i32 0
+  %vecext1 = extractelement <4 x i32> %A, i32 1
+  %add = add i32 %vecext, %vecext1
+  %vecinit = insertelement <4 x i32> undef, i32 %add, i32 0
+  %vecext2 = extractelement <4 x i32> %A, i32 2
+  %vecext3 = extractelement <4 x i32> %A, i32 3
+  %add4 = add i32 %vecext2, %vecext3
+  %vecinit5 = insertelement <4 x i32> %vecinit, i32 %add4, i32 1
+  %vecext6 = extractelement <4 x i32> %B, i32 0
+  %vecext7 = extractelement <4 x i32> %B, i32 1
+  %add8 = add i32 %vecext6, %vecext7
+  %vecinit9 = insertelement <4 x i32> %vecinit5, i32 %add8, i32 2
+  %vecext10 = extractelement <4 x i32> %B, i32 2
+  %vecext11 = extractelement <4 x i32> %B, i32 3
+  %add12 = add i32 %vecext10, %vecext11
+  %vecinit13 = insertelement <4 x i32> %vecinit9, i32 %add12, i32 3
+  ret <4 x i32> %vecinit13
+}
+; CHECK-LABEL: phadd_d_test1
+; SSE3-NOT: phaddd
+; SSSE3: phaddd
+; AVX: vphaddd
+; AVX2 vphaddd
+; CHECK: ret
+
+
+define <4 x i32> @phadd_d_test2(<4 x i32> %A, <4 x i32> %B) {
+  %vecext = extractelement <4 x i32> %A, i32 2
+  %vecext1 = extractelement <4 x i32> %A, i32 3
+  %add = add i32 %vecext, %vecext1
+  %vecinit = insertelement <4 x i32> undef, i32 %add, i32 1
+  %vecext2 = extractelement <4 x i32> %A, i32 0
+  %vecext3 = extractelement <4 x i32> %A, i32 1
+  %add4 = add i32 %vecext2, %vecext3
+  %vecinit5 = insertelement <4 x i32> %vecinit, i32 %add4, i32 0
+  %vecext6 = extractelement <4 x i32> %B, i32 2
+  %vecext7 = extractelement <4 x i32> %B, i32 3
+  %add8 = add i32 %vecext6, %vecext7
+  %vecinit9 = insertelement <4 x i32> %vecinit5, i32 %add8, i32 3
+  %vecext10 = extractelement <4 x i32> %B, i32 0
+  %vecext11 = extractelement <4 x i32> %B, i32 1
+  %add12 = add i32 %vecext10, %vecext11
+  %vecinit13 = insertelement <4 x i32> %vecinit9, i32 %add12, i32 2
+  ret <4 x i32> %vecinit13
+}
+; CHECK-LABEL: phadd_d_test2
+; SSE3-NOT: phaddd
+; SSSE3: phaddd
+; AVX: vphaddd
+; AVX2 vphaddd
+; CHECK: ret
+
+
+define <4 x i32> @phsub_d_test1(<4 x i32> %A, <4 x i32> %B) {
+  %vecext = extractelement <4 x i32> %A, i32 0
+  %vecext1 = extractelement <4 x i32> %A, i32 1
+  %sub = sub i32 %vecext, %vecext1
+  %vecinit = insertelement <4 x i32> undef, i32 %sub, i32 0
+  %vecext2 = extractelement <4 x i32> %A, i32 2
+  %vecext3 = extractelement <4 x i32> %A, i32 3
+  %sub4 = sub i32 %vecext2, %vecext3
+  %vecinit5 = insertelement <4 x i32> %vecinit, i32 %sub4, i32 1
+  %vecext6 = extractelement <4 x i32> %B, i32 0
+  %vecext7 = extractelement <4 x i32> %B, i32 1
+  %sub8 = sub i32 %vecext6, %vecext7
+  %vecinit9 = insertelement <4 x i32> %vecinit5, i32 %sub8, i32 2
+  %vecext10 = extractelement <4 x i32> %B, i32 2
+  %vecext11 = extractelement <4 x i32> %B, i32 3
+  %sub12 = sub i32 %vecext10, %vecext11
+  %vecinit13 = insertelement <4 x i32> %vecinit9, i32 %sub12, i32 3
+  ret <4 x i32> %vecinit13
+}
+; CHECK-LABEL: phsub_d_test1
+; SSE3-NOT: phsubd
+; SSSE3: phsubd
+; AVX: vphsubd
+; AVX2 vphsubd
+; CHECK: ret
+
+
+define <4 x i32> @phsub_d_test2(<4 x i32> %A, <4 x i32> %B) {
+  %vecext = extractelement <4 x i32> %A, i32 2
+  %vecext1 = extractelement <4 x i32> %A, i32 3
+  %sub = sub i32 %vecext, %vecext1
+  %vecinit = insertelement <4 x i32> undef, i32 %sub, i32 1
+  %vecext2 = extractelement <4 x i32> %A, i32 0
+  %vecext3 = extractelement <4 x i32> %A, i32 1
+  %sub4 = sub i32 %vecext2, %vecext3
+  %vecinit5 = insertelement <4 x i32> %vecinit, i32 %sub4, i32 0
+  %vecext6 = extractelement <4 x i32> %B, i32 3
+  %vecext7 = extractelement <4 x i32> %B, i32 2
+  %sub8 = sub i32 %vecext6, %vecext7
+  %vecinit9 = insertelement <4 x i32> %vecinit5, i32 %sub8, i32 3
+  %vecext10 = extractelement <4 x i32> %B, i32 1
+  %vecext11 = extractelement <4 x i32> %B, i32 0
+  %sub12 = sub i32 %vecext10, %vecext11
+  %vecinit13 = insertelement <4 x i32> %vecinit9, i32 %sub12, i32 2
+  ret <4 x i32> %vecinit13
+}
+; CHECK-LABEL: phsub_d_test2
+; SSE3-NOT: phsubd
+; SSSE3: phsubd
+; AVX: vphsubd
+; AVX2 vphsubd
+; CHECK: ret
+
+
+define <2 x double> @hadd_pd_test1(<2 x double> %A, <2 x double> %B) {
+  %vecext = extractelement <2 x double> %A, i32 0
+  %vecext1 = extractelement <2 x double> %A, i32 1
+  %add = fadd double %vecext, %vecext1
+  %vecinit = insertelement <2 x double> undef, double %add, i32 0
+  %vecext2 = extractelement <2 x double> %B, i32 0
+  %vecext3 = extractelement <2 x double> %B, i32 1
+  %add2 = fadd double %vecext2, %vecext3
+  %vecinit2 = insertelement <2 x double> %vecinit, double %add2, i32 1
+  ret <2 x double> %vecinit2
+}
+; CHECK-LABEL: hadd_pd_test1
+; CHECK: haddpd
+; CHECK-NEXT: ret
+
+
+define <2 x double> @hadd_pd_test2(<2 x double> %A, <2 x double> %B) {
+  %vecext = extractelement <2 x double> %A, i32 1
+  %vecext1 = extractelement <2 x double> %A, i32 0
+  %add = fadd double %vecext, %vecext1
+  %vecinit = insertelement <2 x double> undef, double %add, i32 0
+  %vecext2 = extractelement <2 x double> %B, i32 1
+  %vecext3 = extractelement <2 x double> %B, i32 0
+  %add2 = fadd double %vecext2, %vecext3
+  %vecinit2 = insertelement <2 x double> %vecinit, double %add2, i32 1
+  ret <2 x double> %vecinit2
+}
+; CHECK-LABEL: hadd_pd_test2
+; CHECK: haddpd
+; CHECK-NEXT: ret
+
+
+define <2 x double> @hsub_pd_test1(<2 x double> %A, <2 x double> %B) {
+  %vecext = extractelement <2 x double> %A, i32 0
+  %vecext1 = extractelement <2 x double> %A, i32 1
+  %sub = fsub double %vecext, %vecext1
+  %vecinit = insertelement <2 x double> undef, double %sub, i32 0
+  %vecext2 = extractelement <2 x double> %B, i32 0
+  %vecext3 = extractelement <2 x double> %B, i32 1
+  %sub2 = fsub double %vecext2, %vecext3
+  %vecinit2 = insertelement <2 x double> %vecinit, double %sub2, i32 1
+  ret <2 x double> %vecinit2
+}
+; CHECK-LABEL: hsub_pd_test1
+; CHECK: hsubpd
+; CHECK-NEXT: ret
+
+
+define <2 x double> @hsub_pd_test2(<2 x double> %A, <2 x double> %B) {
+  %vecext = extractelement <2 x double> %A, i32 1
+  %vecext1 = extractelement <2 x double> %A, i32 0
+  %sub = fsub double %vecext, %vecext1
+  %vecinit = insertelement <2 x double> undef, double %sub, i32 0
+  %vecext2 = extractelement <2 x double> %B, i32 1
+  %vecext3 = extractelement <2 x double> %B, i32 0
+  %sub2 = fsub double %vecext2, %vecext3
+  %vecinit2 = insertelement <2 x double> %vecinit, double %sub2, i32 1
+  ret <2 x double> %vecinit2
+}
+; CHECK-LABEL: hsub_pd_test2
+; CHECK: hsubpd
+; CHECK-NEXT: ret
+
+
+define <4 x double> @avx_vhadd_pd_test(<4 x double> %A, <4 x double> %B) {
+  %vecext = extractelement <4 x double> %A, i32 0
+  %vecext1 = extractelement <4 x double> %A, i32 1
+  %add = fadd double %vecext, %vecext1
+  %vecinit = insertelement <4 x double> undef, double %add, i32 0
+  %vecext2 = extractelement <4 x double> %A, i32 2
+  %vecext3 = extractelement <4 x double> %A, i32 3
+  %add4 = fadd double %vecext2, %vecext3
+  %vecinit5 = insertelement <4 x double> %vecinit, double %add4, i32 1
+  %vecext6 = extractelement <4 x double> %B, i32 0
+  %vecext7 = extractelement <4 x double> %B, i32 1
+  %add8 = fadd double %vecext6, %vecext7
+  %vecinit9 = insertelement <4 x double> %vecinit5, double %add8, i32 2
+  %vecext10 = extractelement <4 x double> %B, i32 2
+  %vecext11 = extractelement <4 x double> %B, i32 3
+  %add12 = fadd double %vecext10, %vecext11
+  %vecinit13 = insertelement <4 x double> %vecinit9, double %add12, i32 3
+  ret <4 x double> %vecinit13
+}
+; CHECK-LABEL: avx_vhadd_pd_test
+; SSE3: haddpd
+; SSE3-NEXT: haddpd
+; SSSE3: haddpd
+; SSSE3: haddpd
+; AVX: vhaddpd
+; AVX2: vhaddpd
+; CHECK: ret
+
+
+define <4 x double> @avx_vhsub_pd_test(<4 x double> %A, <4 x double> %B) {
+  %vecext = extractelement <4 x double> %A, i32 0
+  %vecext1 = extractelement <4 x double> %A, i32 1
+  %sub = fsub double %vecext, %vecext1
+  %vecinit = insertelement <4 x double> undef, double %sub, i32 0
+  %vecext2 = extractelement <4 x double> %A, i32 2
+  %vecext3 = extractelement <4 x double> %A, i32 3
+  %sub4 = fsub double %vecext2, %vecext3
+  %vecinit5 = insertelement <4 x double> %vecinit, double %sub4, i32 1
+  %vecext6 = extractelement <4 x double> %B, i32 0
+  %vecext7 = extractelement <4 x double> %B, i32 1
+  %sub8 = fsub double %vecext6, %vecext7
+  %vecinit9 = insertelement <4 x double> %vecinit5, double %sub8, i32 2
+  %vecext10 = extractelement <4 x double> %B, i32 2
+  %vecext11 = extractelement <4 x double> %B, i32 3
+  %sub12 = fsub double %vecext10, %vecext11
+  %vecinit13 = insertelement <4 x double> %vecinit9, double %sub12, i32 3
+  ret <4 x double> %vecinit13
+}
+; CHECK-LABEL: avx_vhsub_pd_test
+; SSE3: hsubpd
+; SSE3-NEXT: hsubpd
+; SSSE3: hsubpd
+; SSSE3-NEXT: hsubpd
+; AVX: vhsubpd
+; AVX2: vhsubpd
+; CHECK: ret
+
+
+define <8 x i32> @avx2_vphadd_d_test(<8 x i32> %A, <8 x i32> %B) {
+  %vecext = extractelement <8 x i32> %A, i32 0
+  %vecext1 = extractelement <8 x i32> %A, i32 1
+  %add = add i32 %vecext, %vecext1
+  %vecinit = insertelement <8 x i32> undef, i32 %add, i32 0
+  %vecext2 = extractelement <8 x i32> %A, i32 2
+  %vecext3 = extractelement <8 x i32> %A, i32 3
+  %add4 = add i32 %vecext2, %vecext3
+  %vecinit5 = insertelement <8 x i32> %vecinit, i32 %add4, i32 1
+  %vecext6 = extractelement <8 x i32> %A, i32 4
+  %vecext7 = extractelement <8 x i32> %A, i32 5
+  %add8 = add i32 %vecext6, %vecext7
+  %vecinit9 = insertelement <8 x i32> %vecinit5, i32 %add8, i32 2
+  %vecext10 = extractelement <8 x i32> %A, i32 6
+  %vecext11 = extractelement <8 x i32> %A, i32 7
+  %add12 = add i32 %vecext10, %vecext11
+  %vecinit13 = insertelement <8 x i32> %vecinit9, i32 %add12, i32 3
+  %vecext14 = extractelement <8 x i32> %B, i32 0
+  %vecext15 = extractelement <8 x i32> %B, i32 1
+  %add16 = add i32 %vecext14, %vecext15
+  %vecinit17 = insertelement <8 x i32> %vecinit13, i32 %add16, i32 4
+  %vecext18 = extractelement <8 x i32> %B, i32 2
+  %vecext19 = extractelement <8 x i32> %B, i32 3
+  %add20 = add i32 %vecext18, %vecext19
+  %vecinit21 = insertelement <8 x i32> %vecinit17, i32 %add20, i32 5
+  %vecext22 = extractelement <8 x i32> %B, i32 4
+  %vecext23 = extractelement <8 x i32> %B, i32 5
+  %add24 = add i32 %vecext22, %vecext23
+  %vecinit25 = insertelement <8 x i32> %vecinit21, i32 %add24, i32 6
+  %vecext26 = extractelement <8 x i32> %B, i32 6
+  %vecext27 = extractelement <8 x i32> %B, i32 7
+  %add28 = add i32 %vecext26, %vecext27
+  %vecinit29 = insertelement <8 x i32> %vecinit25, i32 %add28, i32 7
+  ret <8 x i32> %vecinit29
+}
+; CHECK-LABEL: avx2_vphadd_d_test
+; SSE3-NOT: phaddd
+; SSSE3: phaddd
+; SSSE3-NEXT: phaddd
+; AVX-NOT: vphaddd
+; AVX2: vphaddd
+; CHECK: ret
+