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-rw-r--r--llvm/test/Transforms/SimplifyCFG/ForwardSwitchConditionToPHI.ll139
1 files changed, 130 insertions, 9 deletions
diff --git a/llvm/test/Transforms/SimplifyCFG/ForwardSwitchConditionToPHI.ll b/llvm/test/Transforms/SimplifyCFG/ForwardSwitchConditionToPHI.ll
index d6185a1b874f..8ad455eb9e7f 100644
--- a/llvm/test/Transforms/SimplifyCFG/ForwardSwitchConditionToPHI.ll
+++ b/llvm/test/Transforms/SimplifyCFG/ForwardSwitchConditionToPHI.ll
@@ -2,16 +2,10 @@
; RUN: opt < %s -passes=simplifycfg -simplifycfg-require-and-preserve-domtree=1 -forward-switch-cond=false -switch-range-to-icmp -S | FileCheck %s --check-prefix=NO_FWD
; RUN: opt < %s -passes=simplifycfg -simplifycfg-require-and-preserve-domtree=1 -forward-switch-cond=true -switch-range-to-icmp -S | FileCheck %s --check-prefix=FWD
-; RUN: opt < %s -passes='simplifycfg<no-forward-switch-cond;switch-range-to-icmp>' -S | FileCheck %s --check-prefix=NO_FWD
-; RUN: opt < %s -passes='simplifycfg<forward-switch-cond;switch-range-to-icmp>' -S | FileCheck %s --check-prefix=FWD
-
; PR10131
-target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32-n8:16:32"
-target triple = "i386-pc-linux-gnu"
-
-define i32 @t(i32 %m) nounwind readnone {
-; NO_FWD-LABEL: @t(
+define i32 @forward_multiple(i32 %m) {
+; NO_FWD-LABEL: @forward_multiple(
; NO_FWD-NEXT: entry:
; NO_FWD-NEXT: switch i32 [[M:%.*]], label [[SW_BB4:%.*]] [
; NO_FWD-NEXT: i32 0, label [[RETURN:%.*]]
@@ -31,7 +25,7 @@ define i32 @t(i32 %m) nounwind readnone {
; NO_FWD-NEXT: [[RETVAL_0:%.*]] = phi i32 [ 4, [[SW_BB4]] ], [ 3, [[SW_BB3]] ], [ 2, [[SW_BB2]] ], [ 1, [[SW_BB1]] ], [ 0, [[ENTRY:%.*]] ]
; NO_FWD-NEXT: ret i32 [[RETVAL_0]]
;
-; FWD-LABEL: @t(
+; FWD-LABEL: @forward_multiple(
; FWD-NEXT: entry:
; FWD-NEXT: [[SWITCH:%.*]] = icmp ult i32 [[M:%.*]], 4
; FWD-NEXT: [[SPEC_SELECT:%.*]] = select i1 [[SWITCH]], i32 [[M]], i32 4
@@ -65,6 +59,76 @@ return: ; preds = %entry, %sw.bb4, %sw
ret i32 %retval.0
}
+; We should not forward `%m` to 1, as this does not simplify the CFG.
+define i32 @forward_one(i32 %m) {
+; NO_FWD-LABEL: @forward_one(
+; NO_FWD-NEXT: entry:
+; NO_FWD-NEXT: switch i32 [[M:%.*]], label [[SW_BB4:%.*]] [
+; NO_FWD-NEXT: i32 0, label [[RETURN:%.*]]
+; NO_FWD-NEXT: i32 1, label [[SW_BB1:%.*]]
+; NO_FWD-NEXT: i32 2, label [[SW_BB2:%.*]]
+; NO_FWD-NEXT: i32 3, label [[SW_BB3:%.*]]
+; NO_FWD-NEXT: ]
+; NO_FWD: sw.bb1:
+; NO_FWD-NEXT: br label [[RETURN]]
+; NO_FWD: sw.bb2:
+; NO_FWD-NEXT: br label [[RETURN]]
+; NO_FWD: sw.bb3:
+; NO_FWD-NEXT: br label [[RETURN]]
+; NO_FWD: sw.bb4:
+; NO_FWD-NEXT: br label [[RETURN]]
+; NO_FWD: return:
+; NO_FWD-NEXT: [[RETVAL_0:%.*]] = phi i32 [ 4, [[SW_BB4]] ], [ 5, [[SW_BB3]] ], [ 6, [[SW_BB2]] ], [ 1, [[SW_BB1]] ], [ 8, [[ENTRY:%.*]] ]
+; NO_FWD-NEXT: ret i32 [[RETVAL_0]]
+;
+; FWD-LABEL: @forward_one(
+; FWD-NEXT: entry:
+; FWD-NEXT: switch i32 [[M:%.*]], label [[SW_BB4:%.*]] [
+; FWD-NEXT: i32 0, label [[RETURN:%.*]]
+; FWD-NEXT: i32 1, label [[SW_BB1:%.*]]
+; FWD-NEXT: i32 2, label [[SW_BB2:%.*]]
+; FWD-NEXT: i32 3, label [[SW_BB3:%.*]]
+; FWD-NEXT: ]
+; FWD: sw.bb1:
+; FWD-NEXT: br label [[RETURN]]
+; FWD: sw.bb2:
+; FWD-NEXT: br label [[RETURN]]
+; FWD: sw.bb3:
+; FWD-NEXT: br label [[RETURN]]
+; FWD: sw.bb4:
+; FWD-NEXT: br label [[RETURN]]
+; FWD: return:
+; FWD-NEXT: [[RETVAL_0:%.*]] = phi i32 [ 4, [[SW_BB4]] ], [ 5, [[SW_BB3]] ], [ 6, [[SW_BB2]] ], [ 1, [[SW_BB1]] ], [ 8, [[ENTRY:%.*]] ]
+; FWD-NEXT: ret i32 [[RETVAL_0]]
+;
+entry:
+ switch i32 %m, label %sw.bb4 [
+ i32 0, label %sw.bb0
+ i32 1, label %sw.bb1
+ i32 2, label %sw.bb2
+ i32 3, label %sw.bb3
+ ]
+
+sw.bb0: ; preds = %entry
+ br label %return
+
+sw.bb1: ; preds = %entry
+ br label %return
+
+sw.bb2: ; preds = %entry
+ br label %return
+
+sw.bb3: ; preds = %entry
+ br label %return
+
+sw.bb4: ; preds = %entry
+ br label %return
+
+return: ; preds = %entry, %sw.bb4, %sw.bb3, %sw.bb2, %sw.bb1
+ %retval.0 = phi i32 [ 4, %sw.bb4 ], [ 5, %sw.bb3 ], [ 6, %sw.bb2 ], [ 1, %sw.bb1 ], [ 8, %sw.bb0 ]
+ ret i32 %retval.0
+}
+
; If 1 incoming phi value is a case constant of a switch, convert it to the switch condition:
; https://bugs.llvm.org/show_bug.cgi?id=34471
; This then subsequently should allow squashing of the other trivial case blocks.
@@ -121,3 +185,60 @@ return:
ret i32 %r
}
+; We can replace `[ 1, %bb2 ]` with `[ %arg1, %bb2 ]`.
+define { i64, i64 } @PR95919(i64 noundef %arg, i64 noundef %arg1) {
+; NO_FWD-LABEL: @PR95919(
+; NO_FWD-NEXT: bb:
+; NO_FWD-NEXT: switch i64 [[ARG1:%.*]], label [[BB3:%.*]] [
+; NO_FWD-NEXT: i64 0, label [[BB5:%.*]]
+; NO_FWD-NEXT: i64 1, label [[BB2:%.*]]
+; NO_FWD-NEXT: ]
+; NO_FWD: bb2:
+; NO_FWD-NEXT: br label [[BB5]]
+; NO_FWD: bb3:
+; NO_FWD-NEXT: [[I:%.*]] = udiv i64 [[ARG:%.*]], [[ARG1]]
+; NO_FWD-NEXT: [[I4:%.*]] = shl nuw i64 [[I]], 1
+; NO_FWD-NEXT: br label [[BB5]]
+; NO_FWD: bb5:
+; NO_FWD-NEXT: [[I6:%.*]] = phi i64 [ [[I4]], [[BB3]] ], [ [[ARG]], [[BB2]] ], [ undef, [[BB:%.*]] ]
+; NO_FWD-NEXT: [[I7:%.*]] = phi i64 [ 1, [[BB3]] ], [ 1, [[BB2]] ], [ [[ARG1]], [[BB]] ]
+; NO_FWD-NEXT: [[I8:%.*]] = insertvalue { i64, i64 } poison, i64 [[I7]], 0
+; NO_FWD-NEXT: [[I9:%.*]] = insertvalue { i64, i64 } [[I8]], i64 [[I6]], 1
+; NO_FWD-NEXT: ret { i64, i64 } [[I9]]
+;
+; FWD-LABEL: @PR95919(
+; FWD-NEXT: bb:
+; FWD-NEXT: [[SWITCH:%.*]] = icmp ult i64 [[ARG1:%.*]], 2
+; FWD-NEXT: br i1 [[SWITCH]], label [[BB5:%.*]], label [[BB3:%.*]]
+; FWD: bb3:
+; FWD-NEXT: [[I:%.*]] = udiv i64 [[ARG:%.*]], [[ARG1]]
+; FWD-NEXT: [[I4:%.*]] = shl nuw i64 [[I]], 1
+; FWD-NEXT: br label [[BB5]]
+; FWD: bb5:
+; FWD-NEXT: [[I6:%.*]] = phi i64 [ [[I4]], [[BB3]] ], [ [[ARG]], [[BB:%.*]] ]
+; FWD-NEXT: [[I7:%.*]] = phi i64 [ 1, [[BB3]] ], [ [[ARG1]], [[BB]] ]
+; FWD-NEXT: [[I8:%.*]] = insertvalue { i64, i64 } poison, i64 [[I7]], 0
+; FWD-NEXT: [[I9:%.*]] = insertvalue { i64, i64 } [[I8]], i64 [[I6]], 1
+; FWD-NEXT: ret { i64, i64 } [[I9]]
+;
+bb:
+ switch i64 %arg1, label %bb3 [
+ i64 0, label %bb5
+ i64 1, label %bb2
+ ]
+
+bb2: ; preds = %bb
+ br label %bb5
+
+bb3: ; preds = %bb
+ %i = udiv i64 %arg, %arg1
+ %i4 = shl nuw i64 %i, 1
+ br label %bb5
+
+bb5: ; preds = %bb3, %bb2, %bb
+ %i6 = phi i64 [ %i4, %bb3 ], [ %arg, %bb2 ], [ undef, %bb ]
+ %i7 = phi i64 [ 1, %bb3 ], [ 1, %bb2 ], [ %arg1, %bb ]
+ %i8 = insertvalue { i64, i64 } poison, i64 %i7, 0
+ %i9 = insertvalue { i64, i64 } %i8, i64 %i6, 1
+ ret { i64, i64 } %i9
+}
generated by cgit v1.2.3 (git 2.25.1) at 2026-05-31 14:07:19 +0000