[llvm] 0bd5bbb - [X86] Add test showing binary differences with -x86-pad-for-align.
Florian Hahn via llvm-commits
llvm-commits at lists.llvm.org
Thu Jun 17 04:38:12 PDT 2021
Author: Florian Hahn
Date: 2021-06-17T12:27:17+01:00
New Revision: 0bd5bbb31e0345aed8d029d70a4197aed53a3cd5
URL: https://github.com/llvm/llvm-project/commit/0bd5bbb31e0345aed8d029d70a4197aed53a3cd5
DIFF: https://github.com/llvm/llvm-project/commit/0bd5bbb31e0345aed8d029d70a4197aed53a3cd5.diff
LOG: [X86] Add test showing binary differences with -x86-pad-for-align.
This patch adds a test case showing how a single extra .loc can cause
binary differences when using -x86-pad-for-align=true.
The issue has been discussed in D94542, PR42138, PR48742.
Added:
llvm/test/MC/X86/Inputs/pad-align-with-debug.s
llvm/test/MC/X86/Inputs/pad-align-without-debug.s
llvm/test/MC/X86/pad-for-align-debug.s
Modified:
Removed:
################################################################################
diff --git a/llvm/test/MC/X86/Inputs/pad-align-with-debug.s b/llvm/test/MC/X86/Inputs/pad-align-with-debug.s
new file mode 100644
index 0000000000000..56a0378010f8d
--- /dev/null
+++ b/llvm/test/MC/X86/Inputs/pad-align-with-debug.s
@@ -0,0 +1,45 @@
+# See PR48742.
+ .text
+ .p2align 4
+foo:
+ .file 1 "foo.c"
+ movq %rdi, %rax
+ .p2align 4,,10
+ .p2align 3
+L1:
+ movzbl (%rax), %edx
+ cmpb $10, %dl
+ je L4
+L2:
+ cmpb $100, %dl
+ je L5
+ cmpb $200, %dl
+ je L5
+ cmpb $300, %dl
+ jne L5
+ .p2align 4,,10
+ .p2align 3
+L3:
+ movq %rax, %rdx
+ incq %rax
+ cmpb $30, (%rax)
+ jne L3
+ leaq 2(%rdx), %rax
+ movzbl (%rax), %edx
+ .loc 1 1234 5
+ cmpb $90, %dl
+ jne L2
+ .p2align 4,,10
+ .p2align 3
+L4:
+ cmpb $99, 4(%rax)
+ je L7
+L5:
+ incq %rax
+ jmp L1
+ .p2align 4,,10
+ .p2align 3
+L6:
+ ret
+L7:
+ ret
diff --git a/llvm/test/MC/X86/Inputs/pad-align-without-debug.s b/llvm/test/MC/X86/Inputs/pad-align-without-debug.s
new file mode 100644
index 0000000000000..74c27ed887fa4
--- /dev/null
+++ b/llvm/test/MC/X86/Inputs/pad-align-without-debug.s
@@ -0,0 +1,43 @@
+# See PR48742.
+ .text
+ .p2align 4
+foo:
+ movq %rdi, %rax
+ .p2align 4,,10
+ .p2align 3
+L1:
+ movzbl (%rax), %edx
+ cmpb $10, %dl
+ je L4
+L2:
+ cmpb $100, %dl
+ je L5
+ cmpb $200, %dl
+ je L5
+ cmpb $300, %dl
+ jne L5
+ .p2align 4,,10
+ .p2align 3
+L3:
+ movq %rax, %rdx
+ incq %rax
+ cmpb $30, (%rax)
+ jne L3
+ leaq 2(%rdx), %rax
+ movzbl (%rax), %edx
+ cmpb $90, %dl
+ jne L2
+ .p2align 4,,10
+ .p2align 3
+L4:
+ cmpb $99, 4(%rax)
+ je L7
+L5:
+ incq %rax
+ jmp L1
+ .p2align 4,,10
+ .p2align 3
+L6:
+ ret
+L7:
+ ret
diff --git a/llvm/test/MC/X86/pad-for-align-debug.s b/llvm/test/MC/X86/pad-for-align-debug.s
new file mode 100644
index 0000000000000..2e3bed9683c8e
--- /dev/null
+++ b/llvm/test/MC/X86/pad-for-align-debug.s
@@ -0,0 +1,81 @@
+# RUN: llvm-mc -mcpu=skylake -filetype=obj -triple x86_64-apple-macos -x86-pad-for-align=true %S/Inputs/pad-align-with-debug.s | llvm-objdump -d - | FileCheck --check-prefix=CHECK --check-prefix=DEBUG %s
+# RUN: llvm-mc -mcpu=skylake -filetype=obj -triple x86_64-apple-macos -x86-pad-for-align=true %S/Inputs/pad-align-without-debug.s | llvm-objdump -d - | FileCheck --check-prefix=CHECK --check-prefix=NODEBUG %s
+# RUN: llvm-mc -mcpu=skylake -filetype=obj -triple x86_64-apple-macos -x86-pad-for-align=false %S/Inputs/pad-align-without-debug.s | llvm-objdump -d - | FileCheck --check-prefix=NOPAD %s
+# RUN: llvm-mc -mcpu=skylake -filetype=obj -triple x86_64-apple-macos -x86-pad-for-align=false %S/Inputs/pad-align-with-debug.s | llvm-objdump -d - | FileCheck --check-prefix=NOPAD %s
+
+; Test case to show that -x86-pad-for-align causes binary
diff erences in the
+; presence of debug locations. Inputs/pad-align-with-debug.s and
+; Inputs/pad-align-without-debug.s are equivalent, modulo a single .loc, which
+; cause the
diff erence in the binary below. This should be fixed, before
+; x86-pad-for-align=true becomes the default.
+
+; Also see PR48742.
+
+
+; CHECK-LABEL: 0000000000000000 <foo>:
+; CHECK: 0: 48 89 f8 movq %rdi, %rax
+; CHECK-NEXT: 3: 0f 1f 44 00 00 nopl (%rax,%rax)
+; CHECK-NEXT: 8: 0f b6 10 movzbl (%rax), %edx
+; CHECK-NEXT: b: 80 fa 0a cmpb $10, %dl
+; CHECK-NEXT: e: 74 30 je 0x40 <foo+0x40>
+; CHECK-NEXT: 10: 80 fa 64 cmpb $100, %dl
+; CHECK-NEXT: 13: 74 31 je 0x46 <foo+0x46>
+; CHECK-NEXT: 15: 80 fa c8 cmpb $-56, %dl
+; CHECK-NEXT: 18: 74 2c je 0x46 <foo+0x46>
+; CHECK-NEXT: 1a: 80 fa 2c cmpb $44, %dl
+; CHECK-NEXT: 1d: 75 27 jne 0x46 <foo+0x46>
+; CHECK-NEXT: 1f: 90 nop
+; CHECK-NEXT: 20: 48 89 c2 movq %rax, %rdx
+; CHECK-NEXT: 23: 48 ff c0 incq %rax
+; CHECK-NEXT: 26: 80 38 1e cmpb $30, (%rax)
+
+; DEBUG-NEXT: 29: 75 f5 jne 0x20 <foo+0x20>
+; DEBUG-NEXT: 2b: 48 8d 42 02 leaq 2(%rdx), %rax
+; DEBUG-NEXT: 2f: 0f b6 10 movzbl (%rax), %edx
+; DEBUG-NEXT: 32: 80 fa 5a cmpb $90, %dl
+; DEBUG-NEXT: 35: 0f 85 d5 ff ff ff jne 0x10 <foo+0x10>
+; DEBUG-NEXT: 3b: 0f 1f 44 00 00 nopl (%rax,%rax)
+
+; NODEBUG-NEXT: 29: 0f 85 f1 ff ff ff jne 0x20 <foo+0x20>
+; NODEBUG-NEXT: 2f: 48 8d 42 02 leaq 2(%rdx), %rax
+; NODEBUG-NEXT: 33: 0f b6 10 movzbl (%rax), %edx
+; NODEBUG-NEXT: 36: 80 fa 5a cmpb $90, %dl
+; NODEBUG-NEXT: 39: 0f 85 d1 ff ff ff jne 0x10 <foo+0x10>
+; NODEBUG-NEXT: 3f: 90 nop
+
+; CHECK-NEXT: 40: 80 78 04 63 cmpb $99, 4(%rax)
+; CHECK-NEXT: 44: 74 0b je 0x51 <foo+0x51>
+; CHECK-NEXT: 46: 48 ff c0 incq %rax
+; CHECK-NEXT: 49: e9 ba ff ff ff jmp 0x8 <foo+0x8>
+; CHECK-NEXT: 4e: 66 90 nop
+; CHECK-NEXT: 50: c3 retq
+; CHECK-NEXT: 51: c3 retq
+
+; NOPAD: 0: 48 89 f8 movq %rdi, %rax
+; NOPAD-NEXT: 3: 0f 1f 44 00 00 nopl (%rax,%rax)
+; NOPAD-NEXT: 8: 0f b6 10 movzbl (%rax), %edx
+; NOPAD-NEXT: b: 80 fa 0a cmpb $10, %dl
+; NOPAD-NEXT: e: 74 30 je 0x40 <foo+0x40>
+; NOPAD-NEXT: 10: 80 fa 64 cmpb $100, %dl
+; NOPAD-NEXT: 13: 74 31 je 0x46 <foo+0x46>
+; NOPAD-NEXT: 15: 80 fa c8 cmpb $-56, %dl
+; NOPAD-NEXT: 18: 74 2c je 0x46 <foo+0x46>
+; NOPAD-NEXT: 1a: 80 fa 2c cmpb $44, %dl
+; NOPAD-NEXT: 1d: 75 27 jne 0x46 <foo+0x46>
+; NOPAD-NEXT: 1f: 90 nop
+; NOPAD-NEXT: 20: 48 89 c2 movq %rax, %rdx
+; NOPAD-NEXT: 23: 48 ff c0 incq %rax
+; NOPAD-NEXT: 26: 80 38 1e cmpb $30, (%rax)
+; NOPAD-NEXT: 29: 75 f5 jne 0x20 <foo+0x20>
+; NOPAD-NEXT: 2b: 48 8d 42 02 leaq 2(%rdx), %rax
+; NOPAD-NEXT: 2f: 0f b6 10 movzbl (%rax), %edx
+; NOPAD-NEXT: 32: 80 fa 5a cmpb $90, %dl
+; NOPAD-NEXT: 35: 75 d9 jne 0x10 <foo+0x10>
+; NOPAD-NEXT: 37: 66 0f 1f 84 00 00 00 00 00 nopw (%rax,%rax)
+; NOPAD-NEXT: 40: 80 78 04 63 cmpb $99, 4(%rax)
+; NOPAD-NEXT: 44: 74 0b je 0x51 <foo+0x51>
+; NOPAD-NEXT: 46: 48 ff c0 incq %rax
+; NOPAD-NEXT: 49: eb bd jmp 0x8 <foo+0x8>
+; NOPAD-NEXT: 4b: 0f 1f 44 00 00 nopl (%rax,%rax)
+; NOPAD-NEXT: 50: c3 retq
+; NOPAD-NEXT: 51: c3 retq
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