[llvm] [llvm][X86] REX profile for UEFI (PR #138362)
Prabhu Rajasekaran via llvm-commits
llvm-commits at lists.llvm.org
Thu Jun 5 11:14:08 PDT 2025
https://github.com/Prabhuk updated https://github.com/llvm/llvm-project/pull/138362
>From ad84c943ffc3e4a8ef7fc534636a5bb548e646e3 Mon Sep 17 00:00:00 2001
From: prabhukr <prabhukr at google.com>
Date: Fri, 2 May 2025 23:26:45 +0000
Subject: [PATCH 1/6] [llvm][X86] REX profile for UEFI
Use the appropriate REX profile for UEFI X86_64 target.
---
llvm/lib/Target/X86/X86ExpandPseudo.cpp | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/llvm/lib/Target/X86/X86ExpandPseudo.cpp b/llvm/lib/Target/X86/X86ExpandPseudo.cpp
index 398b738b85697..5d1f7f7f0fe9d 100644
--- a/llvm/lib/Target/X86/X86ExpandPseudo.cpp
+++ b/llvm/lib/Target/X86/X86ExpandPseudo.cpp
@@ -302,7 +302,7 @@ bool X86ExpandPseudo::expandMI(MachineBasicBlock &MBB,
}
// Jump to label or value in register.
- bool IsWin64 = STI->isTargetWin64();
+ bool IsWinOrUEFI64 = STI->isTargetWin64() || STI->isTargetUEFI64();
if (Opcode == X86::TCRETURNdi || Opcode == X86::TCRETURNdicc ||
Opcode == X86::TCRETURNdi64 || Opcode == X86::TCRETURNdi64cc) {
unsigned Op;
@@ -339,16 +339,17 @@ bool X86ExpandPseudo::expandMI(MachineBasicBlock &MBB,
}
} else if (Opcode == X86::TCRETURNmi || Opcode == X86::TCRETURNmi64) {
- unsigned Op = (Opcode == X86::TCRETURNmi)
- ? X86::TAILJMPm
- : (IsWin64 ? X86::TAILJMPm64_REX : X86::TAILJMPm64);
+ unsigned Op =
+ (Opcode == X86::TCRETURNmi)
+ ? X86::TAILJMPm
+ : (IsWinOrUEFI64 ? X86::TAILJMPm64_REX : X86::TAILJMPm64);
MachineInstrBuilder MIB = BuildMI(MBB, MBBI, DL, TII->get(Op));
for (unsigned i = 0; i != X86::AddrNumOperands; ++i)
MIB.add(MBBI->getOperand(i));
} else if (Opcode == X86::TCRETURNri64) {
JumpTarget.setIsKill();
BuildMI(MBB, MBBI, DL,
- TII->get(IsWin64 ? X86::TAILJMPr64_REX : X86::TAILJMPr64))
+ TII->get(IsWinOrUEFI64 ? X86::TAILJMPr64_REX : X86::TAILJMPr64))
.add(JumpTarget);
} else {
JumpTarget.setIsKill();
>From 4bf4a25d0ac2bafd71e73daa6b386f8483640bf2 Mon Sep 17 00:00:00 2001
From: prabhukr <prabhukr at google.com>
Date: Tue, 6 May 2025 21:40:53 +0000
Subject: [PATCH 2/6] Add test
---
llvm/test/CodeGen/X86/rex-profile-test.ll | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
create mode 100644 llvm/test/CodeGen/X86/rex-profile-test.ll
diff --git a/llvm/test/CodeGen/X86/rex-profile-test.ll b/llvm/test/CodeGen/X86/rex-profile-test.ll
new file mode 100644
index 0000000000000..9cb590794e0ab
--- /dev/null
+++ b/llvm/test/CodeGen/X86/rex-profile-test.ll
@@ -0,0 +1,18 @@
+;; Test that the UEFI and Windows targets set the rex64 correctly.
+; RUN: llc -mtriple x86_64-uefi %s -o - | FileCheck %s -check-prefix=REX
+; RUN: llc -mtriple x86_64-windows-msvc %s -o - | FileCheck %s -check-prefix=REX
+; RUN: llc -mtriple x86_64-unknown-linux %s -o - | FileCheck %s -check-prefix=NOREX
+
+define void @test_tailjmp(ptr %fptr) {
+; REX-LABEL: test_tailjmp: # @test_tailjmp
+; REX: # %bb.0: # %entry
+; REX-NEXT: rex64 jmpq *%rcx # TAILCALL
+;
+; NOREX-LABEL: test_tailjmp: # @test_tailjmp
+; NOREX: .cfi_startproc
+; NOREX-NEXT: # %bb.0: # %entry
+; NOREX-NEXT: jmpq *%rdi # TAILCALL
+entry:
+ tail call void %fptr()
+ ret void
+}
\ No newline at end of file
>From 4275ba0804ef8531263f6ceabf161c3ac5f11bef Mon Sep 17 00:00:00 2001
From: prabhukr <prabhukr at google.com>
Date: Tue, 6 May 2025 21:42:42 +0000
Subject: [PATCH 3/6] Test formatting fix
---
llvm/test/CodeGen/X86/rex-profile-test.ll | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/llvm/test/CodeGen/X86/rex-profile-test.ll b/llvm/test/CodeGen/X86/rex-profile-test.ll
index 9cb590794e0ab..2eb1b0e4f67fe 100644
--- a/llvm/test/CodeGen/X86/rex-profile-test.ll
+++ b/llvm/test/CodeGen/X86/rex-profile-test.ll
@@ -6,7 +6,7 @@
define void @test_tailjmp(ptr %fptr) {
; REX-LABEL: test_tailjmp: # @test_tailjmp
; REX: # %bb.0: # %entry
-; REX-NEXT: rex64 jmpq *%rcx # TAILCALL
+; REX-NEXT: rex64 jmpq *%rcx # TAILCALL
;
; NOREX-LABEL: test_tailjmp: # @test_tailjmp
; NOREX: .cfi_startproc
>From ccc1d3c1d437db6d50ab8a7d28a1e635d75342e8 Mon Sep 17 00:00:00 2001
From: prabhukr <prabhukr at google.com>
Date: Wed, 7 May 2025 00:23:50 +0000
Subject: [PATCH 4/6] Add another e2e test.
---
llvm/test/CodeGen/X86/musttail-varargs.ll | 1 +
llvm/test/CodeGen/X86/rex-profile-test.ll | 2 +-
2 files changed, 2 insertions(+), 1 deletion(-)
diff --git a/llvm/test/CodeGen/X86/musttail-varargs.ll b/llvm/test/CodeGen/X86/musttail-varargs.ll
index f9b2ce79a35ca..65cd1edd92e31 100644
--- a/llvm/test/CodeGen/X86/musttail-varargs.ll
+++ b/llvm/test/CodeGen/X86/musttail-varargs.ll
@@ -2,6 +2,7 @@
; RUN: llc -verify-machineinstrs < %s -enable-tail-merge=0 -mtriple=x86_64-linux | FileCheck %s --check-prefix=LINUX
; RUN: llc -verify-machineinstrs < %s -enable-tail-merge=0 -mtriple=x86_64-linux-gnux32 | FileCheck %s --check-prefix=LINUX-X32
; RUN: llc -verify-machineinstrs < %s -enable-tail-merge=0 -mtriple=x86_64-windows | FileCheck %s --check-prefix=WINDOWS
+; RUN: llc -verify-machineinstrs < %s -enable-tail-merge=0 -mtriple=x86_64-uefi | FileCheck %s --check-prefix=WINDOWS
; RUN: llc -verify-machineinstrs < %s -enable-tail-merge=0 -mtriple=i686-windows | FileCheck %s --check-prefix=X86 --check-prefix=X86-NOSSE
; RUN: llc -verify-machineinstrs < %s -enable-tail-merge=0 -mtriple=i686-windows -mattr=+sse2 | FileCheck %s --check-prefix=X86 --check-prefix=X86-SSE
diff --git a/llvm/test/CodeGen/X86/rex-profile-test.ll b/llvm/test/CodeGen/X86/rex-profile-test.ll
index 2eb1b0e4f67fe..379d8faa4fc45 100644
--- a/llvm/test/CodeGen/X86/rex-profile-test.ll
+++ b/llvm/test/CodeGen/X86/rex-profile-test.ll
@@ -15,4 +15,4 @@ define void @test_tailjmp(ptr %fptr) {
entry:
tail call void %fptr()
ret void
-}
\ No newline at end of file
+}
>From 1398b0004234acdaad870b680065268b10c3dc08 Mon Sep 17 00:00:00 2001
From: prabhukr <prabhukr at google.com>
Date: Wed, 28 May 2025 22:31:17 +0000
Subject: [PATCH 5/6] Rename local var.
---
llvm/lib/Target/X86/X86ExpandPseudo.cpp | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/llvm/lib/Target/X86/X86ExpandPseudo.cpp b/llvm/lib/Target/X86/X86ExpandPseudo.cpp
index 5d1f7f7f0fe9d..6ab23e99bda3a 100644
--- a/llvm/lib/Target/X86/X86ExpandPseudo.cpp
+++ b/llvm/lib/Target/X86/X86ExpandPseudo.cpp
@@ -301,8 +301,9 @@ bool X86ExpandPseudo::expandMI(MachineBasicBlock &MBB,
X86FL->emitSPUpdate(MBB, MBBI, DL, Offset, /*InEpilogue=*/true);
}
+ // Use this predicate to set REX prefix for X86_64 targets.
+ bool IsX64 = STI->isTargetWin64() || STI->isTargetUEFI64();
// Jump to label or value in register.
- bool IsWinOrUEFI64 = STI->isTargetWin64() || STI->isTargetUEFI64();
if (Opcode == X86::TCRETURNdi || Opcode == X86::TCRETURNdicc ||
Opcode == X86::TCRETURNdi64 || Opcode == X86::TCRETURNdi64cc) {
unsigned Op;
@@ -339,17 +340,16 @@ bool X86ExpandPseudo::expandMI(MachineBasicBlock &MBB,
}
} else if (Opcode == X86::TCRETURNmi || Opcode == X86::TCRETURNmi64) {
- unsigned Op =
- (Opcode == X86::TCRETURNmi)
- ? X86::TAILJMPm
- : (IsWinOrUEFI64 ? X86::TAILJMPm64_REX : X86::TAILJMPm64);
+ unsigned Op = (Opcode == X86::TCRETURNmi)
+ ? X86::TAILJMPm
+ : (IsX64 ? X86::TAILJMPm64_REX : X86::TAILJMPm64);
MachineInstrBuilder MIB = BuildMI(MBB, MBBI, DL, TII->get(Op));
for (unsigned i = 0; i != X86::AddrNumOperands; ++i)
MIB.add(MBBI->getOperand(i));
} else if (Opcode == X86::TCRETURNri64) {
JumpTarget.setIsKill();
BuildMI(MBB, MBBI, DL,
- TII->get(IsWinOrUEFI64 ? X86::TAILJMPr64_REX : X86::TAILJMPr64))
+ TII->get(IsX64 ? X86::TAILJMPr64_REX : X86::TAILJMPr64))
.add(JumpTarget);
} else {
JumpTarget.setIsKill();
>From db4070ba678a8e28a715274fbbe6a4af41c011f6 Mon Sep 17 00:00:00 2001
From: prabhukr <prabhukr at google.com>
Date: Thu, 5 Jun 2025 18:13:36 +0000
Subject: [PATCH 6/6] Fix var name on assert
---
llvm/lib/Target/X86/X86ExpandPseudo.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/llvm/lib/Target/X86/X86ExpandPseudo.cpp b/llvm/lib/Target/X86/X86ExpandPseudo.cpp
index 214c50fd5c084..c7abb367fad28 100644
--- a/llvm/lib/Target/X86/X86ExpandPseudo.cpp
+++ b/llvm/lib/Target/X86/X86ExpandPseudo.cpp
@@ -353,7 +353,7 @@ bool X86ExpandPseudo::expandMI(MachineBasicBlock &MBB,
TII->get(IsX64 ? X86::TAILJMPr64_REX : X86::TAILJMPr64))
.add(JumpTarget);
} else {
- assert(!IsWin64 && "Win64 requires REX for indirect jumps.");
+ assert(!IsX64 && "Win64 and UEFI64 require REX for indirect jumps.");
JumpTarget.setIsKill();
BuildMI(MBB, MBBI, DL, TII->get(X86::TAILJMPr))
.add(JumpTarget);
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