[llvm-branch-commits] [llvm] [AsmPrinter][ELF] Support profile-guided section prefix for jump tables' (read-only) data sections (PR #122215)

[Wei Xiao via llvm-branch-commits]

================
@@ -3,21 +3,53 @@
 
 ; Stop after 'finalize-isel' for simpler MIR, and lower the minimum number of
 ; jump table entries so 'switch' needs fewer cases to generate a jump table.
-; RUN: llc -stop-after=finalize-isel -min-jump-table-entries=2 %s -o %t.mir
-; RUN: llc --run-pass=static-data-splitter -stats -x mir %t.mir -o - 2>&1 | FileCheck %s --check-prefix=STAT
+; RUN: llc -mtriple=x86_64-unknown-linux-gnu -stop-after=finalize-isel -min-jump-table-entries=2 %s -o %t.mir
+; RUN: llc -mtriple=x86_64-unknown-linux-gnu --run-pass=static-data-splitter -stats -x mir %t.mir -o - 2>&1 | FileCheck %s --check-prefix=STAT
 
-; Tests stat messages are expected.
-; TODO: Update test to verify section suffixes when target-lowering and assembler changes are implemented.
-; TODO: Also run static-data-splitter pass with -static-data-default-hotness=cold and check data section suffix.
- 
+ ; Tests stat messages are expected.
 ; STAT-DAG: 2 static-data-splitter - Number of cold jump tables seen
 ; STAT-DAG: 2 static-data-splitter - Number of hot jump tables seen
 ; STAT-DAG: 1 static-data-splitter - Number of jump tables with unknown hotness
 
-; In function @foo, the 2 switch instructions to jt0.* and jt2.* get lowered to hot jump tables,
-; and the 2 switch instructions to jt1.* and jt3.* get lowered to cold jump tables.
-
-; @func_without_profile doesn't have profiles. It's jump table hotness is unknown.
+; When 'partition-static-data-sections' is enabled, static data splitter pass will
+; categorize jump tables and assembly printer will place hot jump tables in the
+; `.rodata.hot`-prefixed section, and cold ones in the `.rodata.unlikely`-prefixed section.
+; Section names will optionally have `.<func>` if -function-sections is enabled.
+; RUN: llc -mtriple=x86_64-unknown-linux-gnu -enable-split-machine-functions -partition-static-data-sections=true -function-sections=true -min-jump-table-entries=2 -unique-section-names=false  %s -o - 2>&1 | FileCheck %s --check-prefixes=LINEAR,JT
+; RUN: llc -mtriple=x86_64-unknown-linux-gnu -enable-split-machine-functions -partition-static-data-sections=true -function-sections=true -min-jump-table-entries=2  %s -o - 2>&1 | FileCheck %s --check-prefixes=FUNC,JT,DEFAULTHOT
+; RUN: llc -mtriple=x86_64-unknown-linux-gnu -enable-split-machine-functions -partition-static-data-sections=true -function-sections=false -min-jump-table-entries=2 %s -o - 2>&1 | FileCheck %s --check-prefixes=FUNCLESS,JT --implicit-check-not=unique
+
+; Tests that `-static-data-default-hotness` can override hotness for data with
+; unknown hotness.
+; RUN: llc -mtriple=x86_64-unknown-linux-gnu -enable-split-machine-functions -partition-static-data-sections=true -min-jump-table-entries=2 -static-data-default-hotness=cold -function-sections=true %s -o - 2>&1 | FileCheck %s --check-prefixes=FUNC,JT,DEFAULTCOLD
+
+; LINEAR:    .section .rodata.hot,"a", at progbits,unique,2
+; FUNC:     .section .rodata.hot.foo,"a", at progbits
+; FUNCLESS: .section .rodata.hot,"a", at progbits
+; JT: .LJTI0_0:
+; JT: .LJTI0_2:
+; LINEAR:    	.section	.rodata.unlikely,"a", at progbits,unique,3
+; FUNC:       .section .rodata.unlikely.foo,"a", at progbits
+; FUNCLESS:   .section .rodata.unlikely,"a", at progbits
+; JT: .LJTI0_1:
+; JT: .LJTI0_3:
+; DEFAULTHOT: .section .rodata.hot.func_without_entry_count,"a", at progbits
----------------
williamweixiao wrote:

According referenced function is inside ".section        .text.func_without_entry_count" but its data in ".section    .rodata.hot.func_without_entry_count". There seems to be some inconsistency here.

https://github.com/llvm/llvm-project/pull/122215