[CodeGenPrepare] Removed duplicate logic. SimplifyCFG already knows how to speculate calls to cttz/ctlz.

SimplifyCFG now knows how to speculate calls to intrinsic cttz/ctlz that are
'cheap' for the target. Therefore, some of the logic in CodeGenPrepare
that was originally added at revision 224899 can now be removed.

This patch is basically a no functional change. It removes the duplicated
logic in CodeGenPrepare and converts all the existing target specific tests
for cttz/ctlz into SimplifyCFG tests.

Differential Revision: http://reviews.llvm.org/D7608

llvm-svn: 229105

2 files changed, 251 insertions, 0 deletions

diff --git a/llvm/test/Transforms/SimplifyCFG/R600/cttz-ctlz.ll b/llvm/test/Transforms/SimplifyCFG/R600/cttz-ctlz.ll
new file mode 100644
index 00000000000..5b279949464
--- /dev/null
+++ b/llvm/test/Transforms/SimplifyCFG/R600/cttz-ctlz.ll
@@ -0,0 +1,249 @@
+; RUN: opt -S -simplifycfg -mtriple=r600-unknown-unknown -mcpu=SI < %s | FileCheck -check-prefix=SI -check-prefix=ALL %s
+; RUN: opt -S -simplifycfg -mtriple=r600-unknown-unknown -mcpu=tonga < %s | FileCheck -check-prefix=SI -check-prefix=ALL %s
+
+
+define i64 @test1(i64 %A) {
+; ALL-LABEL: @test1(
+; SI: [[ICMP:%[A-Za-z0-9]+]] = icmp eq i64 %A, 0
+; SI-NEXT: [[CTLZ:%[A-Za-z0-9]+]] = tail call i64 @llvm.ctlz.i64(i64 %A, i1 true)
+; SI-NEXT: [[SEL:%[A-Za-z0-9.]+]] = select i1 [[ICMP]], i64 64, i64 [[CTLZ]]
+; SI-NEXT: ret i64 [[SEL]]
+entry:
+  %tobool = icmp eq i64 %A, 0
+  br i1 %tobool, label %cond.end, label %cond.true
+
+cond.true:                                        ; preds = %entry
+  %0 = tail call i64 @llvm.ctlz.i64(i64 %A, i1 true)
+  br label %cond.end
+
+cond.end:                                         ; preds = %entry, %cond.true
+  %cond = phi i64 [ %0, %cond.true ], [ 64, %entry ]
+  ret i64 %cond
+}
+
+
+define i32 @test2(i32 %A) {
+; ALL-LABEL: @test2(
+; SI: [[ICMP:%[A-Za-z0-9]+]] = icmp eq i32 %A, 0
+; SI-NEXT: [[CTLZ:%[A-Za-z0-9]+]] = tail call i32 @llvm.ctlz.i32(i32 %A, i1 true)
+; SI-NEXT: [[SEL:%[A-Za-z0-9.]+]] = select i1 [[ICMP]], i32 32, i32 [[CTLZ]]
+; SI-NEXT: ret i32 [[SEL]]
+entry:
+  %tobool = icmp eq i32 %A, 0
+  br i1 %tobool, label %cond.end, label %cond.true
+
+cond.true:                                        ; preds = %entry
+  %0 = tail call i32 @llvm.ctlz.i32(i32 %A, i1 true)
+  br label %cond.end
+
+cond.end:                                         ; preds = %entry, %cond.true
+  %cond = phi i32 [ %0, %cond.true ], [ 32, %entry ]
+  ret i32 %cond
+}
+
+
+define signext i16 @test3(i16 signext %A) {
+; ALL-LABEL: @test3(
+; SI: [[ICMP:%[A-Za-z0-9]+]] = icmp eq i16 %A, 0
+; SI-NEXT: [[CTLZ:%[A-Za-z0-9]+]] = tail call i16 @llvm.ctlz.i16(i16 %A, i1 true)
+; SI-NEXT: [[SEL:%[A-Za-z0-9.]+]] = select i1 [[ICMP]], i16 16, i16 [[CTLZ]]
+; SI-NEXT: ret i16 [[SEL]]
+entry:
+  %tobool = icmp eq i16 %A, 0
+  br i1 %tobool, label %cond.end, label %cond.true
+
+cond.true:                                        ; preds = %entry
+  %0 = tail call i16 @llvm.ctlz.i16(i16 %A, i1 true)
+  br label %cond.end
+
+cond.end:                                         ; preds = %entry, %cond.true
+  %cond = phi i16 [ %0, %cond.true ], [ 16, %entry ]
+  ret i16 %cond
+}
+
+
+define i64 @test1b(i64 %A) {
+; ALL-LABEL: @test1b(
+; SI: [[ICMP:%[A-Za-z0-9]+]] = icmp eq i64 %A, 0
+; SI-NEXT: [[CTTZ:%[A-Za-z0-9]+]] = tail call i64 @llvm.cttz.i64(i64 %A, i1 true)
+; SI-NEXT: [[SEL:%[A-Za-z0-9.]+]] = select i1 [[ICMP]], i64 64, i64 [[CTTZ]]
+; SI-NEXT: ret i64 [[SEL]]
+entry:
+  %tobool = icmp eq i64 %A, 0
+  br i1 %tobool, label %cond.end, label %cond.true
+
+cond.true:                                        ; preds = %entry
+  %0 = tail call i64 @llvm.cttz.i64(i64 %A, i1 true)
+  br label %cond.end
+
+cond.end:                                         ; preds = %entry, %cond.true
+  %cond = phi i64 [ %0, %cond.true ], [ 64, %entry ]
+  ret i64 %cond
+}
+
+
+define i32 @test2b(i32 %A) {
+; ALL-LABEL: @test2b(
+; SI: [[ICMP:%[A-Za-z0-9]+]] = icmp eq i32 %A, 0
+; SI-NEXT: [[CTTZ:%[A-Za-z0-9]+]] = tail call i32 @llvm.cttz.i32(i32 %A, i1 true)
+; SI-NEXT: [[SEL:%[A-Za-z0-9.]+]] = select i1 [[ICMP]], i32 32, i32 [[CTTZ]]
+; SI-NEXT: ret i32 [[SEL]]
+entry:
+  %tobool = icmp eq i32 %A, 0
+  br i1 %tobool, label %cond.end, label %cond.true
+
+cond.true:                                        ; preds = %entry
+  %0 = tail call i32 @llvm.cttz.i32(i32 %A, i1 true)
+  br label %cond.end
+
+cond.end:                                         ; preds = %entry, %cond.true
+  %cond = phi i32 [ %0, %cond.true ], [ 32, %entry ]
+  ret i32 %cond
+}
+
+
+define signext i16 @test3b(i16 signext %A) {
+; ALL-LABEL: @test3b(
+; SI: [[ICMP:%[A-Za-z0-9]+]] = icmp eq i16 %A, 0
+; SI-NEXT: [[CTTZ:%[A-Za-z0-9]+]] = tail call i16 @llvm.cttz.i16(i16 %A, i1 true)
+; SI-NEXT: [[SEL:%[A-Za-z0-9.]+]] = select i1 [[ICMP]], i16 16, i16 [[CTTZ]]
+; SI-NEXT: ret i16 [[SEL]]
+entry:
+  %tobool = icmp eq i16 %A, 0
+  br i1 %tobool, label %cond.end, label %cond.true
+
+cond.true:                                        ; preds = %entry
+  %0 = tail call i16 @llvm.cttz.i16(i16 %A, i1 true)
+  br label %cond.end
+
+cond.end:                                         ; preds = %entry, %cond.true
+  %cond = phi i16 [ %0, %cond.true ], [ 16, %entry ]
+  ret i16 %cond
+}
+
+
+define i64 @test1c(i64 %A) {
+; ALL-LABEL: @test1c(
+; ALL: [[ICMP:%[A-Za-z0-9]+]] = icmp eq i64 %A, 0
+; ALL-NEXT: [[CTLZ:%[A-Za-z0-9]+]] = tail call i64 @llvm.ctlz.i64(i64 %A, i1 true)
+; ALL-NEXT: [[SEL:%[A-Za-z0-9.]+]] = select i1 [[ICMP]], i64 63, i64 [[CTLZ]]
+; ALL-NEXT: ret i64 [[SEL]]
+entry:
+  %tobool = icmp eq i64 %A, 0
+  br i1 %tobool, label %cond.end, label %cond.true
+
+cond.true:                                        ; preds = %entry
+  %0 = tail call i64 @llvm.ctlz.i64(i64 %A, i1 true)
+  br label %cond.end
+
+cond.end:                                         ; preds = %entry, %cond.true
+  %cond = phi i64 [ %0, %cond.true ], [ 63, %entry ]
+  ret i64 %cond
+}
+
+define i32 @test2c(i32 %A) {
+; ALL-LABEL: @test2c(
+; ALL: [[ICMP:%[A-Za-z0-9]+]] = icmp eq i32 %A, 0
+; ALL-NEXT: [[CTLZ:%[A-Za-z0-9]+]] = tail call i32 @llvm.ctlz.i32(i32 %A, i1 true)
+; ALL-NEXT: [[SEL:%[A-Za-z0-9.]+]] = select i1 [[ICMP]], i32 31, i32 [[CTLZ]]
+; ALL-NEXT: ret i32 [[SEL]]
+entry:
+  %tobool = icmp eq i32 %A, 0
+  br i1 %tobool, label %cond.end, label %cond.true
+
+cond.true:                                        ; preds = %entry
+  %0 = tail call i32 @llvm.ctlz.i32(i32 %A, i1 true)
+  br label %cond.end
+
+cond.end:                                         ; preds = %entry, %cond.true
+  %cond = phi i32 [ %0, %cond.true ], [ 31, %entry ]
+  ret i32 %cond
+}
+
+
+define signext i16 @test3c(i16 signext %A) {
+; ALL-LABEL: @test3c(
+; ALL: [[ICMP:%[A-Za-z0-9]+]] = icmp eq i16 %A, 0
+; ALL-NEXT: [[CTLZ:%[A-Za-z0-9]+]] = tail call i16 @llvm.ctlz.i16(i16 %A, i1 true)
+; ALL-NEXT: [[SEL:%[A-Za-z0-9.]+]] = select i1 [[ICMP]], i16 15, i16 [[CTLZ]]
+; ALL-NEXT: ret i16 [[SEL]]
+entry:
+  %tobool = icmp eq i16 %A, 0
+  br i1 %tobool, label %cond.end, label %cond.true
+
+cond.true:                                        ; preds = %entry
+  %0 = tail call i16 @llvm.ctlz.i16(i16 %A, i1 true)
+  br label %cond.end
+
+cond.end:                                         ; preds = %entry, %cond.true
+  %cond = phi i16 [ %0, %cond.true ], [ 15, %entry ]
+  ret i16 %cond
+}
+
+
+define i64 @test1d(i64 %A) {
+; ALL-LABEL: @test1d(
+; ALL: [[ICMP:%[A-Za-z0-9]+]] = icmp eq i64 %A, 0
+; ALL-NEXT: [[CTTZ:%[A-Za-z0-9]+]] = tail call i64 @llvm.cttz.i64(i64 %A, i1 true)
+; ALL-NEXT: [[SEL:%[A-Za-z0-9.]+]] = select i1 [[ICMP]], i64 63, i64 [[CTTZ]]
+; ALL-NEXT: ret i64 [[SEL]]
+entry:
+  %tobool = icmp eq i64 %A, 0
+  br i1 %tobool, label %cond.end, label %cond.true
+
+cond.true:                                        ; preds = %entry
+  %0 = tail call i64 @llvm.cttz.i64(i64 %A, i1 true)
+  br label %cond.end
+
+cond.end:                                         ; preds = %entry, %cond.true
+  %cond = phi i64 [ %0, %cond.true ], [ 63, %entry ]
+  ret i64 %cond
+}
+
+
+define i32 @test2d(i32 %A) {
+; ALL-LABEL: @test2d(
+; ALL: [[ICMP:%[A-Za-z0-9]+]] = icmp eq i32 %A, 0
+; ALL-NEXT: [[CTTZ:%[A-Za-z0-9]+]] = tail call i32 @llvm.cttz.i32(i32 %A, i1 true)
+; ALL-NEXT: [[SEL:%[A-Za-z0-9.]+]] = select i1 [[ICMP]], i32 31, i32 [[CTTZ]]
+; ALL-NEXT: ret i32 [[SEL]]
+entry:
+  %tobool = icmp eq i32 %A, 0
+  br i1 %tobool, label %cond.end, label %cond.true
+
+cond.true:                                        ; preds = %entry
+  %0 = tail call i32 @llvm.cttz.i32(i32 %A, i1 true)
+  br label %cond.end
+
+cond.end:                                         ; preds = %entry, %cond.true
+  %cond = phi i32 [ %0, %cond.true ], [ 31, %entry ]
+  ret i32 %cond
+}
+
+
+define signext i16 @test3d(i16 signext %A) {
+; ALL-LABEL: @test3d(
+; ALL: [[ICMP:%[A-Za-z0-9]+]] = icmp eq i16 %A, 0
+; ALL-NEXT: [[CTTZ:%[A-Za-z0-9]+]] = tail call i16 @llvm.cttz.i16(i16 %A, i1 true)
+; ALL-NEXT: [[SEL:%[A-Za-z0-9.]+]] = select i1 [[ICMP]], i16 15, i16 [[CTTZ]]
+; ALL-NEXT: ret i16 [[SEL]]
+entry:
+  %tobool = icmp eq i16 %A, 0
+  br i1 %tobool, label %cond.end, label %cond.true
+
+cond.true:                                        ; preds = %entry
+  %0 = tail call i16 @llvm.cttz.i16(i16 %A, i1 true)
+  br label %cond.end
+
+cond.end:                                         ; preds = %entry, %cond.true
+  %cond = phi i16 [ %0, %cond.true ], [ 15, %entry ]
+  ret i16 %cond
+}
+
+
+declare i64 @llvm.ctlz.i64(i64, i1)
+declare i32 @llvm.ctlz.i32(i32, i1)
+declare i16 @llvm.ctlz.i16(i16, i1)
+declare i64 @llvm.cttz.i64(i64, i1)
+declare i32 @llvm.cttz.i32(i32, i1)
+declare i16 @llvm.cttz.i16(i16, i1)
diff --git a/llvm/test/Transforms/SimplifyCFG/R600/lit.local.cfg b/llvm/test/Transforms/SimplifyCFG/R600/lit.local.cfg
new file mode 100644
index 00000000000..ad9ce2541ef
--- /dev/null
+++ b/llvm/test/Transforms/SimplifyCFG/R600/lit.local.cfg
@@ -0,0 +1,2 @@
+if not 'R600' in config.root.targets:
+    config.unsupported = True