From: W. Felix Handte <w@felixhandte.com>
Date: Fri, 20 Jan 2023 22:32:49 +0000 (-0500)
Subject: Add Additional Flags to PGO Build
X-Git-Tag: v1.5.4^2~38^2~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=87e169d05d75db5112df20361de33f7398ef27d5;p=thirdparty%2Fzstd.git

Add Additional Flags to PGO Build

In GCC, we can add a couple more flags to give us confidence that the profile
data is actually being found and used.

Also, my system for example doesn't have a binary installed under the name
`llvm-profdata`, but it does have, e.g., `llvm-profdata-13`, etc. So this
commit adds a variable that can be overridden.
---

diff --git a/programs/Makefile b/programs/Makefile
index b79b60b4f..fcff41dc1 100644
--- a/programs/Makefile
+++ b/programs/Makefile
@@ -231,9 +231,12 @@ zstd-dll : zstd
 
 ## zstd-pgo: zstd executable optimized with PGO.
 .PHONY: zstd-pgo
+zstd-pgo : LLVM_PROFDATA?=llvm-profdata
+zstd-pgo : PROF_GENERATE_FLAGS=-fprofile-generate $(if $(findstring gcc,$(CC)),-fprofile-dir=.)
+zstd-pgo : PROF_USE_FLAGS=-fprofile-use $(if $(findstring gcc,$(CC)),-fprofile-dir=. -Werror=missing-profile -Wno-error=coverage-mismatch)
 zstd-pgo :
 	$(MAKE) clean HASH_DIR=$(HASH_DIR)
-	$(MAKE) zstd HASH_DIR=$(HASH_DIR) MOREFLAGS=-fprofile-generate
+	$(MAKE) zstd HASH_DIR=$(HASH_DIR) MOREFLAGS="$(PROF_GENERATE_FLAGS)"
 	./zstd -b19i1 $(PROFILE_WITH)
 	./zstd -b16i1 $(PROFILE_WITH)
 	./zstd -b9i2 $(PROFILE_WITH)
@@ -245,8 +248,8 @@ ifndef BUILD_DIR
 else
 	$(RM) zstd $(BUILD_DIR)/zstd $(BUILD_DIR)/*.o
 endif
-	case $(CC) in *clang*) if ! [ -e default.profdata ]; then llvm-profdata merge -output=default.profdata default*.profraw; fi ;; esac
-	$(MAKE) zstd HASH_DIR=$(HASH_DIR) MOREFLAGS=-fprofile-use
+	case $(CC) in *clang*) if ! [ -e default.profdata ]; then $(LLVM_PROFDATA) merge -output=default.profdata default*.profraw; fi ;; esac
+	$(MAKE) zstd HASH_DIR=$(HASH_DIR) MOREFLAGS="$(PROF_USE_FLAGS)"
 
 ## zstd-small: minimal target, supporting only zstd compression and decompression. no bench. no legacy. no other format.
 CLEAN += zstd-small zstd-frugal