R600: Recommit 199842: Add work-around for the CF stack entry HW bug

The unit test is now disabled on non-asserts builds.

The CF stack can be corrupted if you use CF_ALU_PUSH_BEFORE,
CF_ALU_ELSE_AFTER, CF_ALU_BREAK, or CF_ALU_CONTINUE when the number of
sub-entries on the stack is greater than or equal to the stack entry
size and sub-entries modulo 4 is either 0 or 3 (on cedar the bug is
present when number of sub-entries module 8 is either 7 or 0)

We choose to be conservative and always apply the work-around when the
number of sub-enries is greater than or equal to the stack entry size,
so that we can safely over-allocate the stack when we are unsure of the
stack allocation rules.

reviewed-by: Vincent Lejeune <vljn at ovi.com>
llvm-svn: 199905

1 files changed, 227 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/R600/cf-stack-bug.ll b/llvm/test/CodeGen/R600/cf-stack-bug.ll
new file mode 100644
index 00000000000..c3a4612e6ac
--- /dev/null
+++ b/llvm/test/CodeGen/R600/cf-stack-bug.ll
@@ -0,0 +1,227 @@
+; RUN: llc -march=r600 -mcpu=redwood -debug-only=r600cf %s -o - 2>&1 | FileCheck %s --check-prefix=BUG64 --check-prefix=FUNC
+; RUN: llc -march=r600 -mcpu=sumo -debug-only=r600cf %s -o - 2>&1 | FileCheck %s --check-prefix=BUG64 --check-prefix=FUNC
+; RUN: llc -march=r600 -mcpu=barts -debug-only=r600cf %s -o - 2>&1 | FileCheck %s --check-prefix=BUG64 --check-prefix=FUNC
+; RUN: llc -march=r600 -mcpu=turks -debug-only=r600cf %s -o - 2>&1 | FileCheck %s --check-prefix=BUG64 --check-prefix=FUNC
+; RUN: llc -march=r600 -mcpu=caicos -debug-only=r600cf %s -o - 2>&1 | FileCheck %s --check-prefix=BUG64 --check-prefix=FUNC
+; RUN: llc -march=r600 -mcpu=cedar -debug-only=r600cf %s -o - 2>&1 | FileCheck %s --check-prefix=BUG32 --check-prefix=FUNC
+; RUN: llc -march=r600 -mcpu=juniper -debug-only=r600cf %s -o - 2>&1 | FileCheck %s --check-prefix=NOBUG --check-prefix=FUNC
+; RUN: llc -march=r600 -mcpu=cypress -debug-only=r600cf %s -o - 2>&1 | FileCheck %s --check-prefix=NOBUG --check-prefix=FUNC
+; RUN: llc -march=r600 -mcpu=cayman -debug-only=r600cf %s -o - 2>&1 | FileCheck %s --check-prefix=NOBUG --check-prefix=FUNC
+
+; REQUIRES: asserts
+
+; We are currently allocating 2 extra sub-entries on Evergreen / NI for
+; non-WQM push instructions if we change this to 1, then we will need to
+; add one level of depth to each of these tests.
+
+; BUG64-NOT: Applying bug work-around
+; BUG32-NOT: Applying bug work-around
+; NOBUG-NOT: Applying bug work-around
+; FUNC-LABEL: @nested3
+define void @nested3(i32 addrspace(1)* %out, i32 %cond) {
+entry:
+  %0 = icmp sgt i32 %cond, 0
+  br i1 %0, label %if.1, label %end
+
+if.1:
+  %1 = icmp sgt i32 %cond, 10
+  br i1 %1, label %if.2, label %if.store.1
+
+if.store.1:
+  store i32 1, i32 addrspace(1)* %out
+  br label %end
+
+if.2:
+  %2 = icmp sgt i32 %cond, 20
+  br i1 %2, label %if.3, label %if.2.store
+
+if.2.store:
+  store i32 2, i32 addrspace(1)* %out
+  br label %end
+
+if.3:
+  store i32 3, i32 addrspace(1)* %out
+  br label %end
+
+end:
+  ret void
+}
+
+; BUG64: Applying bug work-around
+; BUG32-NOT: Applying bug work-around
+; NOBUG-NOT: Applying bug work-around
+; FUNC-LABEL: @nested4
+define void @nested4(i32 addrspace(1)* %out, i32 %cond) {
+entry:
+  %0 = icmp sgt i32 %cond, 0
+  br i1 %0, label %if.1, label %end
+
+if.1:
+  %1 = icmp sgt i32 %cond, 10
+  br i1 %1, label %if.2, label %if.1.store
+
+if.1.store:
+  store i32 1, i32 addrspace(1)* %out
+  br label %end
+
+if.2:
+  %2 = icmp sgt i32 %cond, 20
+  br i1 %2, label %if.3, label %if.2.store
+
+if.2.store:
+  store i32 2, i32 addrspace(1)* %out
+  br label %end
+
+if.3:
+  %3 = icmp sgt i32 %cond, 30
+  br i1 %3, label %if.4, label %if.3.store
+
+if.3.store:
+  store i32 3, i32 addrspace(1)* %out
+  br label %end
+
+if.4:
+  store i32 4, i32 addrspace(1)* %out
+  br label %end
+
+end:
+  ret void
+}
+
+; BUG64: Applying bug work-around
+; BUG32-NOT: Applying bug work-around
+; NOBUG-NOT: Applying bug work-around
+; FUNC-LABEL: @nested7
+define void @nested7(i32 addrspace(1)* %out, i32 %cond) {
+entry:
+  %0 = icmp sgt i32 %cond, 0
+  br i1 %0, label %if.1, label %end
+
+if.1:
+  %1 = icmp sgt i32 %cond, 10
+  br i1 %1, label %if.2, label %if.1.store
+
+if.1.store:
+  store i32 1, i32 addrspace(1)* %out
+  br label %end
+
+if.2:
+  %2 = icmp sgt i32 %cond, 20
+  br i1 %2, label %if.3, label %if.2.store
+
+if.2.store:
+  store i32 2, i32 addrspace(1)* %out
+  br label %end
+
+if.3:
+  %3 = icmp sgt i32 %cond, 30
+  br i1 %3, label %if.4, label %if.3.store
+
+if.3.store:
+  store i32 3, i32 addrspace(1)* %out
+  br label %end
+
+if.4:
+  %4 = icmp sgt i32 %cond, 40
+  br i1 %4, label %if.5, label %if.4.store
+
+if.4.store:
+  store i32 4, i32 addrspace(1)* %out
+  br label %end
+
+if.5:
+  %5 = icmp sgt i32 %cond, 50
+  br i1 %5, label %if.6, label %if.5.store
+
+if.5.store:
+  store i32 5, i32 addrspace(1)* %out
+  br label %end
+
+if.6:
+  %6 = icmp sgt i32 %cond, 60
+  br i1 %6, label %if.7, label %if.6.store
+
+if.6.store:
+  store i32 6, i32 addrspace(1)* %out
+  br label %end
+
+if.7:
+  store i32 7, i32 addrspace(1)* %out
+  br label %end
+
+end:
+  ret void
+}
+
+; BUG64: Applying bug work-around
+; BUG32: Applying bug work-around
+; NOBUG-NOT: Applying bug work-around
+; FUNC-LABEL: @nested8
+define void @nested8(i32 addrspace(1)* %out, i32 %cond) {
+entry:
+  %0 = icmp sgt i32 %cond, 0
+  br i1 %0, label %if.1, label %end
+
+if.1:
+  %1 = icmp sgt i32 %cond, 10
+  br i1 %1, label %if.2, label %if.1.store
+
+if.1.store:
+  store i32 1, i32 addrspace(1)* %out
+  br label %end
+
+if.2:
+  %2 = icmp sgt i32 %cond, 20
+  br i1 %2, label %if.3, label %if.2.store
+
+if.2.store:
+  store i32 2, i32 addrspace(1)* %out
+  br label %end
+
+if.3:
+  %3 = icmp sgt i32 %cond, 30
+  br i1 %3, label %if.4, label %if.3.store
+
+if.3.store:
+  store i32 3, i32 addrspace(1)* %out
+  br label %end
+
+if.4:
+  %4 = icmp sgt i32 %cond, 40
+  br i1 %4, label %if.5, label %if.4.store
+
+if.4.store:
+  store i32 4, i32 addrspace(1)* %out
+  br label %end
+
+if.5:
+  %5 = icmp sgt i32 %cond, 50
+  br i1 %5, label %if.6, label %if.5.store
+
+if.5.store:
+  store i32 5, i32 addrspace(1)* %out
+  br label %end
+
+if.6:
+  %6 = icmp sgt i32 %cond, 60
+  br i1 %6, label %if.7, label %if.6.store
+
+if.6.store:
+  store i32 6, i32 addrspace(1)* %out
+  br label %end
+
+if.7:
+  %7 = icmp sgt i32 %cond, 70
+  br i1 %7, label %if.8, label %if.7.store
+
+if.7.store:
+  store i32 7, i32 addrspace(1)* %out
+  br label %end
+
+if.8:
+  store i32 8, i32 addrspace(1)* %out
+  br label %end
+
+end:
+  ret void
+}