[SelectionDAG] Don't treat library calls specially if marked with nobuiltin.

[• koriakin]

Summary

To be used by D19781.

[filcab]

test/CodeGen/SystemZ/memchr-03.ll

4

Please remove -verify-machineinstrs if it's not required.

[filcab]

Can you give the tests more meaningful names?
Something like strlen-nobuiltin.ll explains what it's testing much better than strlen-03.ll.

[• koriakin]

Changed names to -nobuiltin.ll, removed -verify-machineinstrs

[• koriakin]

Ping?

[• koriakin]

Ping?

[• koriakin]

I see the owner has changed in CODE_OWNERS, so... ping?

[• koriakin]

Added an x86-64 test for memcmp + fixed comment. Adding any more targets is pointless, since SystemZ is the only one with custom lowering.

[jvesely]

Hi,

this change breaks OpenCL using mesa (clover) with some library functonis implemneted using builtins:

__attribute__((always_inline)) __attribute__((overloadable)) float copysign(float a, float b) {
    return __builtin_copysignf(a, b)
}

results in kernel build failure:

<unknown>:0:0: in function test_1_copysign_float void (float addrspace(1)*, float addrspace(1)*, float addrspace(1)*): unsupported call to function copysignf

Both for R600 (evergreen) and GCN (kaveri)

[jvesely]

In D19801#465894, @jvesely wrote:

Hi,

this change breaks OpenCL using mesa (clover) with some library functonis implemneted using builtins:

__attribute__((always_inline)) __attribute__((overloadable)) float copysign(float a, float b) {
    return __builtin_copysignf(a, b)
}

results in kernel build failure:

<unknown>:0:0: in function test_1_copysign_float void (float addrspace(1)*, float addrspace(1)*, float addrspace(1)*): unsupported call to function copysignf

Both for R600 (evergreen) and GCN (kaveri)

nvm, libclc was using -fno-builtins and __builtins.

Jan

lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

if (F->isDeclaration()) {
         if (!RenameFn)
           return;
       }
     }
 
     // Check for well-known libc/libm calls.  If the function is internal, it
     // can't be a library call.
     LibFunc::Func Func;
-    if (!F->hasLocalLinkage() && F->hasName() &&
+    if (!I.isNoBuiltin() && !F->hasLocalLinkage() && F->hasName() &&
         LibInfo->getLibFunc(F->getName(), Func) &&
         LibInfo->hasOptimizedCodeGen(Func)) {
       switch (Func) {
       default: break;
       case LibFunc::copysign:
       case LibFunc::copysignf:
       case LibFunc::copysignl:
         if (I.getNumArgOperands() == 2 &&   // Basic sanity checks.

test/CodeGen/SystemZ/memchr-03.ll

+; Test that memchr won't be converted to SRST if calls are
+; marked with nobuiltin, eg. for sanitizers.
+;
+; RUN: llc < %s -mtriple=s390x-linux-gnu -verify-machineinstrs | FileCheck %s
+
+declare i8 *@memchr(i8 *%src, i16 %char, i32 %len)
+
+; Test a simple forwarded call.
+define i8 *@f1(i8 *%src, i16 %char, i32 %len) {
+; CHECK-LABEL: f1:
+; CHECK-NOT: srst
+; CHECK: brasl %r14, memchr
+; CHECK: br %r14
+  %res = call i8 *@memchr(i8 *%src, i16 %char, i32 %len) nobuiltin
+  ret i8 *%res
+}

test/CodeGen/SystemZ/memcmp-03.ll

+; Test that memcmp won't be converted to CLC if calls are
+; marked with nobuiltin, eg. for sanitizers.
+;
+; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
+
+declare signext i32 @memcmp(i8 *%src1, i8 *%src2, i64 %size)
+
+; Zero-length comparisons should be optimized away.
+define i32 @f1(i8 *%src1, i8 *%src2) {
+; CHECK-LABEL: f1:
+; CHECK-NOT: clc
+; CHECK: brasl %r14, memcmp
+; CHECK: br %r14
+  %res = call i32 @memcmp(i8 *%src1, i8 *%src2, i64 0) nobuiltin
+  ret i32 %res
+}
+
+; Check a case where the result is used as an integer.
+define i32 @f2(i8 *%src1, i8 *%src2) {
+; CHECK-LABEL: f2:
+; CHECK-NOT: clc
+; CHECK: brasl %r14, memcmp
+; CHECK: br %r14
+  %res = call i32 @memcmp(i8 *%src1, i8 *%src2, i64 2) nobuiltin
+  ret i32 %res
+}
+
+; Check a case where the result is tested for equality.
+define void @f3(i8 *%src1, i8 *%src2, i32 *%dest) {
+; CHECK-LABEL: f3:
+; CHECK-NOT: clc
+; CHECK: brasl %r14, memcmp
+; CHECK: br %r14
+  %res = call i32 @memcmp(i8 *%src1, i8 *%src2, i64 3) nobuiltin
+  %cmp = icmp eq i32 %res, 0
+  br i1 %cmp, label %exit, label %store
+
+store:
+  store i32 0, i32 *%dest
+  br label %exit
+
+exit:
+  ret void
+}
+
+; Check a case where the result is tested for inequality.
+define void @f4(i8 *%src1, i8 *%src2, i32 *%dest) {
+; CHECK-LABEL: f4:
+; CHECK-NOT: clc
+; CHECK: brasl %r14, memcmp
+; CHECK: br %r14
+entry:
+  %res = call i32 @memcmp(i8 *%src1, i8 *%src2, i64 4) nobuiltin
+  %cmp = icmp ne i32 %res, 0
+  br i1 %cmp, label %exit, label %store
+
+store:
+  store i32 0, i32 *%dest
+  br label %exit
+
+exit:
+  ret void
+}
+
+; Check a case where the result is tested via slt.
+define void @f5(i8 *%src1, i8 *%src2, i32 *%dest) {
+; CHECK-LABEL: f5:
+; CHECK-NOT: clc
+; CHECK: brasl %r14, memcmp
+; CHECK: br %r14
+entry:
+  %res = call i32 @memcmp(i8 *%src1, i8 *%src2, i64 5) nobuiltin
+  %cmp = icmp slt i32 %res, 0
+  br i1 %cmp, label %exit, label %store
+
+store:
+  store i32 0, i32 *%dest
+  br label %exit
+
+exit:
+  ret void
+}
+
+; Check a case where the result is tested for sgt.
+define void @f6(i8 *%src1, i8 *%src2, i32 *%dest) {
+; CHECK-LABEL: f6:
+; CHECK-NOT: clc
+; CHECK: brasl %r14, memcmp
+; CHECK: br %r14
+entry:
+  %res = call i32 @memcmp(i8 *%src1, i8 *%src2, i64 6) nobuiltin
+  %cmp = icmp sgt i32 %res, 0
+  br i1 %cmp, label %exit, label %store
+
+store:
+  store i32 0, i32 *%dest
+  br label %exit
+
+exit:
+  ret void
+}
+
+; Check the upper end of the CLC range.  Here the result is used both as
+; an integer and for branching.
+define i32 @f7(i8 *%src1, i8 *%src2, i32 *%dest) {
+; CHECK-LABEL: f7:
+; CHECK-NOT: clc
+; CHECK: brasl %r14, memcmp
+; CHECK: br %r14
+entry:
+  %res = call i32 @memcmp(i8 *%src1, i8 *%src2, i64 256) nobuiltin
+  %cmp = icmp slt i32 %res, 0
+  br i1 %cmp, label %exit, label %store
+
+store:
+  store i32 0, i32 *%dest
+  br label %exit
+
+exit:
+  ret i32 %res
+}
+
+; 257 bytes needs two CLCs.
+define i32 @f8(i8 *%src1, i8 *%src2) {
+; CHECK-LABEL: f8:
+; CHECK-NOT: clc
+; CHECK: brasl %r14, memcmp
+; CHECK: br %r14
+  %res = call i32 @memcmp(i8 *%src1, i8 *%src2, i64 257) nobuiltin
+  ret i32 %res
+}
+
+; Test a comparison of 258 bytes in which the CC result can be used directly.
+define void @f9(i8 *%src1, i8 *%src2, i32 *%dest) {
+; CHECK-LABEL: f9:
+; CHECK-NOT: clc
+; CHECK: brasl %r14, memcmp
+; CHECK: br %r14
+entry:
+  %res = call i32 @memcmp(i8 *%src1, i8 *%src2, i64 257) nobuiltin
+  %cmp = icmp slt i32 %res, 0
+  br i1 %cmp, label %exit, label %store
+
+store:
+  store i32 0, i32 *%dest
+  br label %exit
+
+exit:
+  ret void
+}
+
+; Test the largest size that can use two CLCs.
+define i32 @f10(i8 *%src1, i8 *%src2) {
+; CHECK-LABEL: f10:
+; CHECK-NOT: clc
+; CHECK: brasl %r14, memcmp
+; CHECK: br %r14
+  %res = call i32 @memcmp(i8 *%src1, i8 *%src2, i64 512) nobuiltin
+  ret i32 %res
+}
+
+; Test the smallest size that needs 3 CLCs.
+define i32 @f11(i8 *%src1, i8 *%src2) {
+; CHECK-LABEL: f11:
+; CHECK-NOT: clc
+; CHECK: brasl %r14, memcmp
+; CHECK: br %r14
+  %res = call i32 @memcmp(i8 *%src1, i8 *%src2, i64 513) nobuiltin
+  ret i32 %res
+}
+
+; Test the largest size than can use 3 CLCs.
+define i32 @f12(i8 *%src1, i8 *%src2) {
+; CHECK-LABEL: f12:
+; CHECK-NOT: clc
+; CHECK: brasl %r14, memcmp
+; CHECK: br %r14
+  %res = call i32 @memcmp(i8 *%src1, i8 *%src2, i64 768) nobuiltin
+  ret i32 %res
+}
+
+; The next size up uses a loop instead.  We leave the more complicated
+; loop tests to memcpy-01.ll, which shares the same form.
+define i32 @f13(i8 *%src1, i8 *%src2) {
+; CHECK-LABEL: f13:
+; CHECK-NOT: clc
+; CHECK: brasl %r14, memcmp
+; CHECK: br %r14
+  %res = call i32 @memcmp(i8 *%src1, i8 *%src2, i64 769) nobuiltin
+  ret i32 %res
+}

test/CodeGen/SystemZ/strcmp-03.ll

+; Test that strcmp won't be converted to CLST if calls are
+; marked with nobuiltin, eg. for sanitizers.
+;
+; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
+
+declare signext i32 @strcmp(i8 *%src1, i8 *%src2)
+
+; Check a case where the result is used as an integer.
+define i32 @f1(i8 *%src1, i8 *%src2) {
+; CHECK-LABEL: f1:
+; CHECK-NOT: clst
+; CHECK: brasl %r14, strcmp
+; CHECK: br %r14
+  %res = call i32 @strcmp(i8 *%src1, i8 *%src2) nobuiltin
+  ret i32 %res
+}
+
+; Check a case where the result is tested for equality.
+define void @f2(i8 *%src1, i8 *%src2, i32 *%dest) {
+; CHECK-LABEL: f2:
+; CHECK-NOT: clst
+; CHECK: brasl %r14, strcmp
+; CHECK: br %r14
+  %res = call i32 @strcmp(i8 *%src1, i8 *%src2) nobuiltin
+  %cmp = icmp eq i32 %res, 0
+  br i1 %cmp, label %exit, label %store
+
+store:
+  store i32 0, i32 *%dest
+  br label %exit
+
+exit:
+  ret void
+}
+
+; Test a case where the result is used both as an integer and for
+; branching.
+define i32 @f3(i8 *%src1, i8 *%src2, i32 *%dest) {
+; CHECK-LABEL: f3:
+; CHECK-NOT: clst
+; CHECK: brasl %r14, strcmp
+; CHECK: br %r14
+entry:
+  %res = call i32 @strcmp(i8 *%src1, i8 *%src2) nobuiltin
+  %cmp = icmp slt i32 %res, 0
+  br i1 %cmp, label %exit, label %store
+
+store:
+  store i32 0, i32 *%dest
+  br label %exit
+
+exit:
+  ret i32 %res
+}

test/CodeGen/SystemZ/strcpy-02.ll

+; Test that strcmp won't be converted to MVST if calls are
+; marked with nobuiltin, eg. for sanitizers.
+;
+; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
+
+declare i8 *@strcpy(i8 *%dest, i8 *%src)
+declare i8 *@stpcpy(i8 *%dest, i8 *%src)
+
+; Check strcpy.
+define i8 *@f1(i8 *%dest, i8 *%src) {
+; CHECK-LABEL: f1:
+; CHECK-NOT: mvst
+; CHECK: brasl %r14, strcpy
+; CHECK: br %r14
+  %res = call i8 *@strcpy(i8 *%dest, i8 *%src) nobuiltin
+  ret i8 *%res
+}
+
+; Check stpcpy.
+define i8 *@f2(i8 *%dest, i8 *%src) {
+; CHECK-LABEL: f2:
+; CHECK-NOT: mvst
+; CHECK: brasl %r14, stpcpy
+; CHECK: br %r14
+  %res = call i8 *@stpcpy(i8 *%dest, i8 *%src) nobuiltin
+  ret i8 *%res
+}
+
+; Check correct operation with other loads and stores.  The load must
+; come before the loop and the store afterwards.
+define i32 @f3(i32 %dummy, i8 *%dest, i8 *%src, i32 *%resptr, i32 *%storeptr) {
+; CHECK-LABEL: f3:
+; CHECK-DAG: l [[REG1:%r[0-9]+]], 0(%r5)
+; CHECK-NOT: mvst
+; CHECK: brasl %r14, strcpy
+; CHECK: mvhi 0(%r6), 0
+; CHECK: br %r14
+  %res = load i32 , i32 *%resptr
+  %unused = call i8 *@strcpy(i8 *%dest, i8 *%src) nobuiltin
+  store i32 0, i32 *%storeptr
+  ret i32 %res
+}

test/CodeGen/SystemZ/strlen-03.ll

+; Test that strlen/strnlen won't be converted to SRST if calls are
+; marked with nobuiltin, eg. for sanitizers.
+;
+; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
+
+declare i64 @strlen(i8 *%src)
+declare i64 @strnlen(i8 *%src, i64 %len)
+
+define i64 @f1(i32 %dummy, i8 *%src) {
+; CHECK-LABEL: f1:
+; CHECK: brasl %r14, strlen
+; CHECK: br %r14
+  %res = call i64 @strlen(i8 *%src) nobuiltin
+  ret i64 %res
+}
+
+; Likewise for strnlen.
+define i64 @f2(i64 %len, i8 *%src) {
+; CHECK-LABEL: f2:
+; CHECK-NOT: srst
+; CHECK: brasl %r14, strnlen
+; CHECK: br %r14
+  %res = call i64 @strnlen(i8 *%src, i64 %len) nobuiltin
+  ret i64 %res
+}