[Stackmap] Liveness Analysis Pass
This optional register liveness analysis pass can be enabled with either
-enable-stackmap-liveness, -enable-patchpoint-liveness, or both. The pass
traverses each basic block in a machine function. For each basic block the
instructions are processed in reversed order and if a patchpoint or stackmap
instruction is encountered the current live-out register set is encoded as a
register mask and attached to the instruction.
Later on during stackmap generation the live-out register mask is processed and
also emitted as part of the stackmap.
This information is optional and intended for optimization purposes only. This
will enable a client of the stackmap to reason about the registers it can use
and which registers need to be preserved.
Reviewed by Andy
llvm-svn: 197317
diff --git a/llvm/test/CodeGen/X86/stackmap-liveness.ll b/llvm/test/CodeGen/X86/stackmap-liveness.ll
new file mode 100644
index 0000000..b1a931d
--- /dev/null
+++ b/llvm/test/CodeGen/X86/stackmap-liveness.ll
@@ -0,0 +1,178 @@
+; RUN: llc < %s -mtriple=x86_64-apple-darwin -mcpu=corei7-avx -disable-fp-elim | FileCheck %s
+; RUN: llc < %s -mtriple=x86_64-apple-darwin -mcpu=corei7-avx -disable-fp-elim -enable-stackmap-liveness| FileCheck -check-prefix=STACK %s
+; RUN: llc < %s -mtriple=x86_64-apple-darwin -mcpu=corei7-avx -disable-fp-elim -enable-patchpoint-liveness| FileCheck -check-prefix=PATCH %s
+;
+; Note: Print verbose stackmaps using -debug-only=stackmaps.
+
+; CHECK-LABEL: .section __LLVM_STACKMAPS,__llvm_stackmaps
+; CHECK-NEXT: __LLVM_StackMaps:
+; CHECK-NEXT: .long 0
+; Num LargeConstants
+; CHECK-NEXT: .long 0
+; Num Callsites
+; CHECK-NEXT: .long 5
+define void @stackmap_liveness() {
+entry:
+ %a1 = call <2 x double> asm sideeffect "", "={xmm2}"() nounwind
+; StackMap 1 (no liveness information available)
+; CHECK-LABEL: .long L{{.*}}-_stackmap_liveness
+; CHECK-NEXT: .short 0
+; CHECK-NEXT: .short 0
+; Num LiveOut Entries: 0
+; CHECK-NEXT: .short 0
+
+; StackMap 1 (stackmap liveness information enabled)
+; STACK-LABEL: .long L{{.*}}-_stackmap_liveness
+; STACK-NEXT: .short 0
+; STACK-NEXT: .short 0
+; Num LiveOut Entries: 2
+; STACK-NEXT: .short 2
+; LiveOut Entry 1: %RSP (8 bytes)
+; STACK-NEXT: .short 7
+; STACK-NEXT: .byte 0
+; STACK-NEXT: .byte 8
+; LiveOut Entry 2: %YMM2 (16 bytes) --> %XMM2
+; STACK-NEXT: .short 19
+; STACK-NEXT: .byte 0
+; STACK-NEXT: .byte 16
+
+; StackMap 1 (patchpoint liveness information enabled)
+; PATCH-LABEL: .long L{{.*}}-_stackmap_liveness
+; PATCH-NEXT: .short 0
+; PATCH-NEXT: .short 0
+; Num LiveOut Entries: 0
+; PATCH-NEXT: .short 0
+ call void (i64, i32, ...)* @llvm.experimental.stackmap(i64 1, i32 5)
+ %a2 = call i64 asm sideeffect "", "={r8}"() nounwind
+ %a3 = call i8 asm sideeffect "", "={ah}"() nounwind
+ %a4 = call <4 x double> asm sideeffect "", "={ymm0}"() nounwind
+ %a5 = call <4 x double> asm sideeffect "", "={ymm1}"() nounwind
+
+; StackMap 2 (no liveness information available)
+; CHECK-LABEL: .long L{{.*}}-_stackmap_liveness
+; CHECK-NEXT: .short 0
+; CHECK-NEXT: .short 0
+; Num LiveOut Entries: 0
+; CHECK-NEXT: .short 0
+
+; StackMap 2 (stackmap liveness information enabled)
+; STACK-LABEL: .long L{{.*}}-_stackmap_liveness
+; STACK-NEXT: .short 0
+; STACK-NEXT: .short 0
+; Num LiveOut Entries: 6
+; STACK-NEXT: .short 6
+; LiveOut Entry 2: %RAX (1 bytes) --> %AL or %AH
+; STACK-NEXT: .short 0
+; STACK-NEXT: .byte 0
+; STACK-NEXT: .byte 1
+; LiveOut Entry 2: %RSP (8 bytes)
+; STACK-NEXT: .short 7
+; STACK-NEXT: .byte 0
+; STACK-NEXT: .byte 8
+; LiveOut Entry 2: %R8 (8 bytes)
+; STACK-NEXT: .short 8
+; STACK-NEXT: .byte 0
+; STACK-NEXT: .byte 8
+; LiveOut Entry 2: %YMM0 (32 bytes)
+; STACK-NEXT: .short 17
+; STACK-NEXT: .byte 0
+; STACK-NEXT: .byte 32
+; LiveOut Entry 2: %YMM1 (32 bytes)
+; STACK-NEXT: .short 18
+; STACK-NEXT: .byte 0
+; STACK-NEXT: .byte 32
+; LiveOut Entry 2: %YMM2 (16 bytes) --> %XMM2
+; STACK-NEXT: .short 19
+; STACK-NEXT: .byte 0
+; STACK-NEXT: .byte 16
+
+; StackMap 2 (patchpoint liveness information enabled)
+; PATCH-LABEL: .long L{{.*}}-_stackmap_liveness
+; PATCH-NEXT: .short 0
+; PATCH-NEXT: .short 0
+; Num LiveOut Entries: 0
+; PATCH-NEXT: .short 0
+ call void (i64, i32, ...)* @llvm.experimental.stackmap(i64 2, i32 5)
+ call void asm sideeffect "", "{r8},{ah},{ymm0},{ymm1}"(i64 %a2, i8 %a3, <4 x double> %a4, <4 x double> %a5) nounwind
+
+; StackMap 3 (no liveness information available)
+; CHECK-LABEL: .long L{{.*}}-_stackmap_liveness
+; CHECK-NEXT: .short 0
+; CHECK-NEXT: .short 0
+; Num LiveOut Entries: 0
+; CHECK-NEXT: .short 0
+
+; StackMap 3 (stackmap liveness information enabled)
+; STACK-LABEL: .long L{{.*}}-_stackmap_liveness
+; STACK-NEXT: .short 0
+; STACK-NEXT: .short 0
+; Num LiveOut Entries: 2
+; STACK-NEXT: .short 2
+; LiveOut Entry 2: %RSP (8 bytes)
+; STACK-NEXT: .short 7
+; STACK-NEXT: .byte 0
+; STACK-NEXT: .byte 8
+; LiveOut Entry 2: %YMM2 (16 bytes) --> %XMM2
+; STACK-NEXT: .short 19
+; STACK-NEXT: .byte 0
+; STACK-NEXT: .byte 16
+
+; StackMap 3 (patchpoint liveness information enabled)
+; PATCH-LABEL: .long L{{.*}}-_stackmap_liveness
+; PATCH-NEXT: .short 0
+; PATCH-NEXT: .short 0
+; Num LiveOut Entries: 0
+; PATCH-NEXT: .short 0
+ call void (i64, i32, ...)* @llvm.experimental.stackmap(i64 3, i32 5)
+ call void asm sideeffect "", "{xmm2}"(<2 x double> %a1) nounwind
+ ret void
+}
+
+define void @mixed_liveness() {
+entry:
+ %a1 = call <2 x double> asm sideeffect "", "={xmm2}"() nounwind
+; StackMap 4 (stackmap liveness information enabled)
+; STACK-LABEL: .long L{{.*}}-_mixed_liveness
+; STACK-NEXT: .short 0
+; STACK-NEXT: .short 0
+; Num LiveOut Entries: 1
+; STACK-NEXT: .short 1
+; LiveOut Entry 1: %YMM2 (16 bytes) --> %XMM2
+; STACK-NEXT: .short 19
+; STACK-NEXT: .byte 0
+; STACK-NEXT: .byte 16
+; StackMap 5 (stackmap liveness information enabled)
+; STACK-LABEL: .long L{{.*}}-_mixed_liveness
+; STACK-NEXT: .short 0
+; STACK-NEXT: .short 0
+; Num LiveOut Entries: 0
+; STACK-NEXT: .short 0
+
+; StackMap 4 (patchpoint liveness information enabled)
+; PATCH-LABEL: .long L{{.*}}-_mixed_liveness
+; PATCH-NEXT: .short 0
+; PATCH-NEXT: .short 0
+; Num LiveOut Entries: 0
+; PATCH-NEXT: .short 0
+; StackMap 5 (patchpoint liveness information enabled)
+; PATCH-LABEL: .long L{{.*}}-_mixed_liveness
+; PATCH-NEXT: .short 0
+; PATCH-NEXT: .short 0
+; Num LiveOut Entries: 2
+; PATCH-NEXT: .short 2
+; LiveOut Entry 1: %RSP (8 bytes)
+; PATCH-NEXT: .short 7
+; PATCH-NEXT: .byte 0
+; PATCH-NEXT: .byte 8
+; LiveOut Entry 1: %YMM2 (16 bytes) --> %XMM2
+; PATCH-NEXT: .short 19
+; PATCH-NEXT: .byte 0
+; PATCH-NEXT: .byte 16
+ call void (i64, i32, ...)* @llvm.experimental.stackmap(i64 4, i32 5)
+ call anyregcc void (i64, i32, i8*, i32, ...)* @llvm.experimental.patchpoint.void(i64 5, i32 0, i8* null, i32 0)
+ call void asm sideeffect "", "{xmm2}"(<2 x double> %a1) nounwind
+ ret void
+}
+
+declare void @llvm.experimental.stackmap(i64, i32, ...)
+declare void @llvm.experimental.patchpoint.void(i64, i32, i8*, i32, ...)