From: Richard Sandiford <rsandifo@linux.vnet.ibm.com>
Date: Fri, 12 Jul 2013 09:17:10 +0000 (+0000)
Subject: [SystemZ] Optimize sign-extends of vector setccs
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=9bcad42c3aadab118b6ed5f30f2ea0d87228fd3f;p=oota-llvm.git

[SystemZ] Optimize sign-extends of vector setccs

Normal (sext (setcc ...)) sequences are optimised into
(select_cc ..., -1, 0) by DAGCombiner::visitSIGN_EXTEND.
However, this is deliberately not done for vectors, and after
vector type legalization we have (sext_inreg (setcc ...)) instead.

I wondered about trying to extend DAGCombiner to handle this case too,
but it seemed to be a loss on some other targets I tried, even those for
which SETCC isn't "legal" and SELECT_CC is.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186149 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Target/SystemZ/SystemZInstrInfo.td b/lib/Target/SystemZ/SystemZInstrInfo.td
index 5e13c7f3461..c47e04b3cfb 100644
--- a/lib/Target/SystemZ/SystemZInstrInfo.td
+++ b/lib/Target/SystemZ/SystemZInstrInfo.td
@@ -1073,3 +1073,12 @@ def  : Pat<(add GR64:$src1, imm64zx32n:$src2),
            (SLGFI GR64:$src1, imm64zx32n:$src2)>;
 def  : Pat<(sub GR64:$src1, (zextloadi32 bdxaddr20only:$addr)),
            (SLGF GR64:$src1, bdxaddr20only:$addr)>;
+
+// Optimize sign-extended 1/0 selects to -1/0 selects.  This is important
+// for vector legalization.
+def : Pat<(sra (shl (i32 (z_select_ccmask 1, 0, imm:$cc)), (i32 31)), (i32 31)),
+          (Select32 (LHI -1), (LHI 0), imm:$cc)>;
+def : Pat<(sra (shl (i64 (anyext (i32 (z_select_ccmask 1, 0, imm:$cc)))),
+                    (i32 63)),
+               (i32 63)),
+          (Select64 (LGHI -1), (LGHI 0), imm:$cc)>;
diff --git a/test/CodeGen/SystemZ/branch-07.ll b/test/CodeGen/SystemZ/branch-07.ll
index 00e8b8a95f7..d009af2f1f0 100644
--- a/test/CodeGen/SystemZ/branch-07.ll
+++ b/test/CodeGen/SystemZ/branch-07.ll
@@ -4,6 +4,7 @@
 
 declare i64 @foo()
 
+; Test EQ.
 define void @f1(i64 %target) {
 ; CHECK: f1:
 ; CHECK: .cfi_def_cfa_offset
@@ -18,6 +19,7 @@ exit:
   ret void
 }
 
+; Test NE.
 define void @f2(i64 %target) {
 ; CHECK: f2:
 ; CHECK: .cfi_def_cfa_offset
@@ -32,6 +34,7 @@ exit:
   ret void
 }
 
+; Test SLE.
 define void @f3(i64 %target) {
 ; CHECK: f3:
 ; CHECK: .cfi_def_cfa_offset
@@ -46,6 +49,7 @@ exit:
   ret void
 }
 
+; Test SLT.
 define void @f4(i64 %target) {
 ; CHECK: f4:
 ; CHECK: .cfi_def_cfa_offset
@@ -60,6 +64,7 @@ exit:
   ret void
 }
 
+; Test SGT.
 define void @f5(i64 %target) {
 ; CHECK: f5:
 ; CHECK: .cfi_def_cfa_offset
@@ -74,6 +79,7 @@ exit:
   ret void
 }
 
+; Test SGE.
 define void @f6(i64 %target) {
 ; CHECK: f6:
 ; CHECK: .cfi_def_cfa_offset
@@ -87,3 +93,67 @@ loop:
 exit:
   ret void
 }
+
+; Test a vector of 0/-1 results for i32 EQ.
+define i64 @f7(i64 %a, i64 %b) {
+; CHECK: f7:
+; CHECK: lhi [[REG:%r[0-5]]], -1
+; CHECK: crje {{%r[0-5]}}
+; CHECK: lhi [[REG]], 0
+; CHECK-NOT: sra
+; CHECK: br %r14
+  %avec = bitcast i64 %a to <2 x i32>
+  %bvec = bitcast i64 %b to <2 x i32>
+  %cmp = icmp eq <2 x i32> %avec, %bvec
+  %ext = sext <2 x i1> %cmp to <2 x i32>
+  %ret = bitcast <2 x i32> %ext to i64
+  ret i64 %ret
+}
+
+; Test a vector of 0/-1 results for i32 NE.
+define i64 @f8(i64 %a, i64 %b) {
+; CHECK: f8:
+; CHECK: lhi [[REG:%r[0-5]]], -1
+; CHECK: crjlh {{%r[0-5]}}
+; CHECK: lhi [[REG]], 0
+; CHECK-NOT: sra
+; CHECK: br %r14
+  %avec = bitcast i64 %a to <2 x i32>
+  %bvec = bitcast i64 %b to <2 x i32>
+  %cmp = icmp ne <2 x i32> %avec, %bvec
+  %ext = sext <2 x i1> %cmp to <2 x i32>
+  %ret = bitcast <2 x i32> %ext to i64
+  ret i64 %ret
+}
+
+; Test a vector of 0/-1 results for i64 EQ.
+define void @f9(i64 %a, i64 %b, <2 x i64> *%dest) {
+; CHECK: f9:
+; CHECK: lghi [[REG:%r[0-5]]], -1
+; CHECK: crje {{%r[0-5]}}
+; CHECK: lghi [[REG]], 0
+; CHECK-NOT: sra
+; CHECK: br %r14
+  %avec = bitcast i64 %a to <2 x i32>
+  %bvec = bitcast i64 %b to <2 x i32>
+  %cmp = icmp eq <2 x i32> %avec, %bvec
+  %ext = sext <2 x i1> %cmp to <2 x i64>
+  store <2 x i64> %ext, <2 x i64> *%dest
+  ret void
+}
+
+; Test a vector of 0/-1 results for i64 NE.
+define void @f10(i64 %a, i64 %b, <2 x i64> *%dest) {
+; CHECK: f10:
+; CHECK: lghi [[REG:%r[0-5]]], -1
+; CHECK: crjlh {{%r[0-5]}}
+; CHECK: lghi [[REG]], 0
+; CHECK-NOT: sra
+; CHECK: br %r14
+  %avec = bitcast i64 %a to <2 x i32>
+  %bvec = bitcast i64 %b to <2 x i32>
+  %cmp = icmp ne <2 x i32> %avec, %bvec
+  %ext = sext <2 x i1> %cmp to <2 x i64>
+  store <2 x i64> %ext, <2 x i64> *%dest
+  ret void
+}