[CGP] Make optimizeMemoryInst able to combine more kinds of ExtAddrMode fields

This patch extends the recent work in optimizeMemoryInst to make it able to
combine more ExtAddrMode fields than just the BaseReg.

This fixes some benchmark regressions introduced by r309397, where GVN PRE is
hoisting a getelementptr such that it can no longer be combined into the
addressing mode of the load or store that uses it.

Differential Revision: https://reviews.llvm.org/D38133

llvm-svn: 318949

1 files changed, 351 insertions, 1 deletions

diff --git a/llvm/test/Transforms/CodeGenPrepare/ARM/sink-addrmode.ll b/llvm/test/Transforms/CodeGenPrepare/ARM/sink-addrmode.ll
index 06a513543c4..0be9c556f93 100644
--- a/llvm/test/Transforms/CodeGenPrepare/ARM/sink-addrmode.ll
+++ b/llvm/test/Transforms/CodeGenPrepare/ARM/sink-addrmode.ll
@@ -1,7 +1,194 @@
-; RUN: opt -S -codegenprepare -mtriple=thumbv7m -disable-complex-addr-modes=false -addr-sink-new-select=true < %s | FileCheck %s
+; RUN: opt -S -codegenprepare -mtriple=thumbv7m -disable-complex-addr-modes=false -addr-sink-new-select=true -addr-sink-new-phis=true < %s | FileCheck %s
 
 target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
 
+@gv1 = common global i32 0, align 4
+@gv2 = common global i32 0, align 4
+
+; Phi selects between ptr and gep with ptr as base and constant offset
+define void @test_phi_onegep_offset(i32* %ptr, i32 %value) {
+; CHECK-LABEL: @test_phi_onegep_offset
+; CHECK-NOT: phi i32* [ %ptr, %entry ], [ %gep, %if.then ]
+; CHECK: phi i32 [ 4, %if.then ], [ 0, %entry ]
+entry:
+  %cmp = icmp sgt i32 %value, 0
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:
+  %gep = getelementptr inbounds i32, i32* %ptr, i32 1
+  br label %if.end
+
+if.end:
+  %phi = phi i32* [ %ptr, %entry ], [ %gep, %if.then ]
+  store i32 %value, i32* %phi, align 4
+  ret void
+}
+
+; Phi selects between two geps with same base, different constant offsets
+define void @test_phi_twogep_offset(i32* %ptr, i32 %value) {
+; CHECK-LABEL: @test_phi_twogep_offset
+; CHECK-NOT: phi i32* [ %gep1, %if.then ], [ %gep2, %if.else ]
+; CHECK: phi i32 [ 8, %if.else ], [ 4, %if.then ]
+entry:
+  %cmp = icmp sgt i32 %value, 0
+  br i1 %cmp, label %if.then, label %if.else
+
+if.then:
+  %gep1 = getelementptr inbounds i32, i32* %ptr, i32 1
+  br label %if.end
+
+if.else:
+  %gep2 = getelementptr inbounds i32, i32* %ptr, i32 2
+  br label %if.end
+
+if.end:
+  %phi = phi i32* [ %gep1, %if.then ], [ %gep2, %if.else ]
+  store i32 %value, i32* %phi, align 4
+  ret void
+}
+
+; Phi selects between ptr and gep with ptr as base and nonconstant offset
+define void @test_phi_onegep_nonconst_offset(i32* %ptr, i32 %value, i32 %off) {
+; CHECK-LABEL: @test_phi_onegep_nonconst_offset
+; CHECK-NOT: phi i32* [ %ptr, %entry ], [ %gep, %if.then ]
+; CHECK: phi i32 [ %off, %if.then ], [ 0, %entry ]
+entry:
+  %cmp = icmp sgt i32 %value, 0
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:
+  %gep = getelementptr inbounds i32, i32* %ptr, i32 %off
+  br label %if.end
+
+if.end:
+  %phi = phi i32* [ %ptr, %entry ], [ %gep, %if.then ]
+  store i32 %value, i32* %phi, align 4
+  ret void
+}
+
+; Phi selects between two geps with same base, different nonconstant offsets
+define void @test_phi_twogep_nonconst_offset(i32* %ptr, i32 %value, i32 %off1, i32 %off2) {
+; CHECK-LABEL: @test_phi_twogep_nonconst_offset
+; CHECK-NOT: phi i32* [ %gep1, %if.then ], [ %gep2, %if.else ]
+; CHECK: phi i32 [ %off2, %if.else ], [ %off1, %if.then ]
+entry:
+  %cmp = icmp sgt i32 %value, 0
+  br i1 %cmp, label %if.then, label %if.else
+
+if.then:
+  %gep1 = getelementptr inbounds i32, i32* %ptr, i32 %off1
+  br label %if.end
+
+if.else:
+  %gep2 = getelementptr inbounds i32, i32* %ptr, i32 %off2
+  br label %if.end
+
+if.end:
+  %phi = phi i32* [ %gep1, %if.then ], [ %gep2, %if.else ]
+  store i32 %value, i32* %phi, align 4
+  ret void
+}
+
+; Phi selects between two geps with different base, same constant offset
+define void @test_phi_twogep_base(i32* %ptr1, i32* %ptr2, i32 %value) {
+; CHECK-LABEL: @test_phi_twogep_base
+; CHECK-NOT: phi i32* [ %gep1, %if.then ], [ %gep2, %if.else ]
+; CHECK: phi i32* [ %ptr2, %if.else ], [ %ptr1, %if.then ]
+entry:
+  %cmp = icmp sgt i32 %value, 0
+  br i1 %cmp, label %if.then, label %if.else
+
+if.then:
+  %gep1 = getelementptr inbounds i32, i32* %ptr1, i32 1
+  br label %if.end
+
+if.else:
+  %gep2 = getelementptr inbounds i32, i32* %ptr2, i32 1
+  br label %if.end
+
+if.end:
+  %phi = phi i32* [ %gep1, %if.then ], [ %gep2, %if.else ]
+  store i32 %value, i32* %phi, align 4
+  ret void
+}
+
+; Phi selects between two geps with different base global variables, same constant offset
+define void @test_phi_twogep_base_gv(i32 %value) {
+; CHECK-LABEL: @test_phi_twogep_base_gv
+; CHECK-NOT: phi i32* [ %gep1, %if.then ], [ %gep2, %if.else ]
+; CHECK: phi i32* [ @gv2, %if.else ], [ @gv1, %if.then ]
+entry:
+  %cmp = icmp sgt i32 %value, 0
+  br i1 %cmp, label %if.then, label %if.else
+
+if.then:
+  %gep1 = getelementptr inbounds i32, i32* @gv1, i32 1
+  br label %if.end
+
+if.else:
+  %gep2 = getelementptr inbounds i32, i32* @gv2, i32 1
+  br label %if.end
+
+if.end:
+  %phi = phi i32* [ %gep1, %if.then ], [ %gep2, %if.else ]
+  store i32 %value, i32* %phi, align 4
+  ret void
+}
+
+; Phi selects between ptr and gep with ptr as base and constant offset
+define void @test_select_onegep_offset(i32* %ptr, i32 %value) {
+; CHECK-LABEL: @test_select_onegep_offset
+; CHECK-NOT: select i1 %cmp, i32* %ptr, i32* %gep
+; CHECK: select i1 %cmp, i32 0, i32 4
+entry:
+  %cmp = icmp sgt i32 %value, 0
+  %gep = getelementptr inbounds i32, i32* %ptr, i32 1
+  %select = select i1 %cmp, i32* %ptr, i32* %gep
+  store i32 %value, i32* %select, align 4
+  ret void
+}
+
+; Select between two geps with same base, different constant offsets
+define void @test_select_twogep_offset(i32* %ptr, i32 %value) {
+; CHECK-LABEL: @test_select_twogep_offset
+; CHECK-NOT: select i1 %cmp, i32* %gep1, i32* %gep2
+; CHECK: select i1 %cmp, i32 4, i32 8
+entry:
+  %cmp = icmp sgt i32 %value, 0
+  %gep1 = getelementptr inbounds i32, i32* %ptr, i32 1
+  %gep2 = getelementptr inbounds i32, i32* %ptr, i32 2
+  %select = select i1 %cmp, i32* %gep1, i32* %gep2
+  store i32 %value, i32* %select, align 4
+  ret void
+}
+
+; Select between ptr and gep with ptr as base and nonconstant offset
+define void @test_select_onegep_nonconst_offset(i32* %ptr, i32 %value, i32 %off) {
+; CHECK-LABEL: @test_select_onegep_nonconst_offset
+; CHECK-NOT: select i1 %cmp, i32* %ptr, i32* %gep
+; CHECK: select i1 %cmp, i32 0, i32 %off
+entry:
+  %cmp = icmp sgt i32 %value, 0
+  %gep = getelementptr inbounds i32, i32* %ptr, i32 %off
+  %select = select i1 %cmp, i32* %ptr, i32* %gep
+  store i32 %value, i32* %select, align 4
+  ret void
+}
+
+; Select between two geps with same base, different nonconstant offsets
+define void @test_select_twogep_nonconst_offset(i32* %ptr, i32 %value, i32 %off1, i32 %off2) {
+; CHECK-LABEL: @test_select_twogep_nonconst_offset
+; CHECK-NOT: select i1 %cmp, i32* %gep1, i32* %gep2
+; CHECK: select i1 %cmp, i32 %off1, i32 %off2
+entry:
+  %cmp = icmp sgt i32 %value, 0
+  %gep1 = getelementptr inbounds i32, i32* %ptr, i32 %off1
+  %gep2 = getelementptr inbounds i32, i32* %ptr, i32 %off2
+  %select = select i1 %cmp, i32* %gep1, i32* %gep2
+  store i32 %value, i32* %select, align 4
+  ret void
+}
+
 ; Select between two geps with different base, same constant offset
 define void @test_select_twogep_base(i32* %ptr1, i32* %ptr2, i32 %value) {
 ; CHECK-LABEL: @test_select_twogep_base
@@ -16,3 +203,166 @@ entry:
   ret void
 }
 
+; Select between two geps with different base global variables, same constant offset
+define void @test_select_twogep_base_gv(i32 %value) {
+; CHECK-LABEL: @test_select_twogep_base_gv
+; CHECK-NOT: select i1 %cmp, i32* %gep1, i32* %gep2
+; CHECK: select i1 %cmp, i32* @gv1, i32* @gv2
+entry:
+  %cmp = icmp sgt i32 %value, 0
+  %gep1 = getelementptr inbounds i32, i32* @gv1, i32 1
+  %gep2 = getelementptr inbounds i32, i32* @gv2, i32 1
+  %select = select i1 %cmp, i32* %gep1, i32* %gep2
+  store i32 %value, i32* %select, align 4
+  ret void
+}
+
+; If the phi is in a different block to where the gep will be, the phi goes where
+; the original phi was not where the gep is.
+; CHECK-LABEL: @test_phi_different_block
+; CHECK-LABEL: if1.end
+; CHECK-NOT: phi i32* [ %ptr, %entry ], [ %gep, %if1.then ]
+; CHECK: phi i32 [ 4, %if1.then ], [ 0, %entry ]
+define void @test_phi_different_block(i32* %ptr, i32 %value1, i32 %value2) {
+entry:
+  %cmp1 = icmp sgt i32 %value1, 0
+  br i1 %cmp1, label %if1.then, label %if1.end
+
+if1.then:
+  %gep = getelementptr inbounds i32, i32* %ptr, i32 1
+  br label %if1.end
+
+if1.end:
+  %phi = phi i32* [ %ptr, %entry ], [ %gep, %if1.then ]
+  %cmp2 = icmp sgt i32 %value2, 0
+  br i1 %cmp2, label %if2.then, label %if2.end
+
+if2.then:
+  store i32 %value1, i32* %ptr, align 4
+  br label %if2.end
+
+if2.end:
+  store i32 %value2, i32* %phi, align 4
+  ret void
+}
+
+; A phi with three incoming values should be optimised
+; CHECK-LABEL: @test_phi_threegep
+; CHECK-NOT: phi i32* [ %gep1, %if.then ], [ %gep2, %if.else.then ], [ %gep3, %if.else.else ]
+; CHECK: phi i32 [ 12, %if.else.else ], [ 8, %if.else.then ], [ 4, %if.then ]
+define void @test_phi_threegep(i32* %ptr, i32 %value1, i32 %value2) {
+entry:
+  %cmp1 = icmp sgt i32 %value1, 0
+  br i1 %cmp1, label %if.then, label %if.else
+
+if.then:
+  %gep1 = getelementptr inbounds i32, i32* %ptr, i32 1
+  br label %if.end
+
+if.else:
+  %cmp2 = icmp sgt i32 %value2, 0
+  br i1 %cmp2, label %if.else.then, label %if.else.else
+
+if.else.then:
+  %gep2 = getelementptr inbounds i32, i32* %ptr, i32 2
+  br label %if.end
+
+if.else.else:
+  %gep3 = getelementptr inbounds i32, i32* %ptr, i32 3
+  br label %if.end
+
+if.end:
+  %phi = phi i32* [ %gep1, %if.then ], [ %gep2, %if.else.then ], [ %gep3, %if.else.else ]
+  store i32 %value1, i32* %phi, align 4
+  ret void
+}
+
+; A phi with two incoming values but three geps due to nesting should be
+; optimised
+; CHECK-LABEL: @test_phi_threegep_nested
+; CHECK: %[[PHI:[a-z0-9_]+]] = phi i32 [ 12, %if.else.else ], [ 8, %if.else.then ]
+; CHECK: phi i32 [ %[[PHI]], %if.else.end ], [ 4, %if.then ]
+define void @test_phi_threegep_nested(i32* %ptr, i32 %value1, i32 %value2) {
+entry:
+  %cmp1 = icmp sgt i32 %value1, 0
+  br i1 %cmp1, label %if.then, label %if.else
+
+if.then:
+  %gep1 = getelementptr inbounds i32, i32* %ptr, i32 1
+  br label %if.end
+
+if.else:
+  %cmp2 = icmp sgt i32 %value2, 0
+  br i1 %cmp2, label %if.else.then, label %if.else.else
+
+if.else.then:
+  %gep2 = getelementptr inbounds i32, i32* %ptr, i32 2
+  br label %if.else.end
+
+if.else.else:
+  %gep3 = getelementptr inbounds i32, i32* %ptr, i32 3
+  br label %if.else.end
+
+if.else.end:
+  %gep4 = phi i32* [ %gep2, %if.else.then ], [ %gep3, %if.else.else ]
+  store i32 %value2, i32* %ptr, align 4
+  br label %if.end
+
+if.end:
+  %phi = phi i32* [ %gep1, %if.then ], [ %gep4, %if.else.end ]
+  store i32 %value1, i32* %phi, align 4
+  ret void
+}
+
+; A nested select is expected to be optimised
+; CHECK-LABEL: @test_nested_select
+; CHECK: %[[SELECT:[a-z0-9_]+]] = select i1 %cmp2, i32 4, i32 8
+; CHECK: select i1 %cmp1, i32 4, i32 %[[SELECT]]
+define void @test_nested_select(i32* %ptr, i32 %value1, i32 %value2) {
+entry:
+  %gep1 = getelementptr inbounds i32, i32* %ptr, i32 1
+  %gep2 = getelementptr inbounds i32, i32* %ptr, i32 2
+  %cmp1 = icmp sgt i32 %value1, 0
+  %cmp2 = icmp sgt i32 %value2, 0
+  %select1 = select i1 %cmp2, i32* %gep1, i32* %gep2
+  %select2 = select i1 %cmp1, i32* %gep1, i32* %select1
+  store i32 %value1, i32* %select2, align 4
+  ret void
+}
+
+; Scaling the offset by a different amount is expected not to be optimised
+; CHECK-LABEL: @test_select_different_scale
+; CHECK: select i1 %cmp, i32* %gep1, i32* %castgep
+define void @test_select_different_scale(i32* %ptr, i32 %value, i32 %off) {
+entry:
+  %cmp = icmp sgt i32 %value, 0
+  %castptr = bitcast i32* %ptr to i16*
+  %gep1 = getelementptr inbounds i32, i32* %ptr, i32 %off
+  %gep2 = getelementptr inbounds i16, i16* %castptr, i32 %off
+  %castgep = bitcast i16* %gep2 to i32*
+  %select = select i1 %cmp, i32* %gep1, i32* %castgep
+  store i32 %value, i32* %select, align 4
+  ret void
+}
+
+; A select between two values is already the best we can do
+; CHECK-LABEL: @test_select_trivial
+; CHECK: select i1 %cmp, i32* %ptr1, i32* %ptr2
+define void @test_select_trivial(i32* %ptr1, i32* %ptr2, i32 %value) {
+entey:
+  %cmp = icmp sgt i32 %value, 0
+  %select = select i1 %cmp, i32* %ptr1, i32* %ptr2
+  store i32 %value, i32* %select, align 4
+  ret void
+}
+
+; A select between two global variables is already the best we can do
+; CHECK-LABEL: @test_select_trivial_gv
+; CHECK: select i1 %cmp, i32* @gv1, i32* @gv2
+define void @test_select_trivial_gv(i32 %value) {
+entey:
+  %cmp = icmp sgt i32 %value, 0
+  %select = select i1 %cmp, i32* @gv1, i32* @gv2
+  store i32 %value, i32* %select, align 4
+  ret void
+}