[RISCV] Set ShouldSignExtI32Param in TargetLibraryInfo for riscv64.

[craig.topper]

Summary

riscv64 sign extends signed and unsigned i32 arguments like Mips.

Based on discussion here
https://discourse.llvm.org/t/can-we-preserve-signext-return-attribute-when-converting-memcmp-to-bcmp/67126

I'll work on returns next.

[efriedma]

LGTM

(see also D133949)

[jyknight]

So, I guess these have all been getting actually miscompiled on riscv64 up till now? Whoops!

[craig.topper]

In D139893#3990451, @jyknight wrote:

So, I guess these have all been getting actually miscompiled on riscv64 up till now? Whoops!

We're fairly aggressive about type legalizing i32 values via sign extension so we might accidentally get it right in a lot of cases.

llvm/lib/Analysis/TargetLibraryInfo.cpp

bool ShouldExtI32Param = false, ShouldExtI32Return = false,
        ShouldSignExtI32Param = false;
   // PowerPC64, Sparc64, SystemZ need signext/zeroext on i32 parameters and
   // returns corresponding to C-level ints and unsigned ints.
   if (T.isPPC64() || T.getArch() == Triple::sparcv9 ||
       T.getArch() == Triple::systemz) {
     ShouldExtI32Param = true;
     ShouldExtI32Return = true;
   }
-  // Mips, on the other hand, needs signext on i32 parameters corresponding
-  // to both signed and unsigned ints.
-  if (T.isMIPS()) {
+  // Mips and riscv64, on the other hand, needs signext on i32 parameters
+  // corresponding to both signed and unsigned ints.
+  if (T.isMIPS() || T.isRISCV64()) {
     ShouldSignExtI32Param = true;
   }
   TLI.setShouldExtI32Param(ShouldExtI32Param);
   TLI.setShouldExtI32Return(ShouldExtI32Return);
   TLI.setShouldSignExtI32Param(ShouldSignExtI32Param);
 
   // Let's assume by default that the size of int is 32 bits, unless the target
   // is a 16-bit architecture because then it most likely is 16 bits. If that

llvm/test/Transforms/InstCombine/RISCV/libcall-arg-exts.ll

+; RUN: opt < %s -passes=instcombine -S -mtriple=riscv64 | FileCheck %s
+;
+; Check that i32 arguments to generated libcalls have the proper extension
+; attributes.
+
+
+declare double @exp2(double)
+declare float @exp2f(float)
+declare fp128 @exp2l(fp128)
+
+define double @fun1(i32 %x) {
+; CHECK-LABEL: @fun1
+; CHECK: call double @ldexp
+  %conv = sitofp i32 %x to double
+  %ret = call double @exp2(double %conv)
+  ret double %ret
+}
+
+define float @fun2(i32 %x) {
+; CHECK-LABEL: @fun2
+; CHECK: call float @ldexpf
+  %conv = sitofp i32 %x to float
+  %ret = call float @exp2f(float %conv)
+  ret float %ret
+}
+
+define fp128 @fun3(i8 zeroext %x) {
+; CHECK-LABEL: @fun3
+; CHECK: call fp128 @ldexpl
+  %conv = uitofp i8 %x to fp128
+  %ret = call fp128 @exp2l(fp128 %conv)
+  ret fp128 %ret
+}
+
+@a = common global [60 x i8] zeroinitializer, align 1
+@b = common global [60 x i8] zeroinitializer, align 1
+declare ptr @__memccpy_chk(ptr, ptr, i32, i64, i64)
+define ptr @fun4() {
+; CHECK-LABEL: @fun4
+; CHECK: call ptr @memccpy
+  %ret = call ptr @__memccpy_chk(ptr @a, ptr @b, i32 0, i64 60, i64 -1)
+  ret ptr %ret
+}
+
+%FILE = type { }
+@A = constant [2 x i8] c"A\00"
+declare i32 @fputs(ptr, ptr)
+define void @fun5(ptr %fp) {
+; CHECK-LABEL: @fun5
+; CHECK: call i32 @fputc
+  call i32 @fputs(ptr @A, ptr %fp)
+  ret void
+}
+
+@empty = constant [1 x i8] zeroinitializer
+declare i32 @puts(ptr)
+define void @fun6() {
+; CHECK-LABEL: @fun6
+; CHECK: call i32 @putchar
+  call i32 @puts(ptr @empty)
+  ret void
+}
+
+@.str1 = private constant [2 x i8] c"a\00"
+declare ptr @strstr(ptr, ptr)
+define ptr @fun7(ptr %str) {
+; CHECK-LABEL: @fun7
+; CHECK: call ptr @strchr
+  %ret = call ptr @strstr(ptr %str, ptr @.str1)
+  ret ptr %ret
+}
+
+; CHECK: declare ptr @strchr(ptr, i32 signext)
+
+@hello = constant [14 x i8] c"hello world\5Cn\00"
+@chp = global ptr zeroinitializer
+declare ptr @strchr(ptr, i32)
+define void @fun8(i32 %chr) {
+; CHECK-LABEL: @fun8
+; CHECK: call ptr @memchr
+  %dst = call ptr @strchr(ptr @hello, i32 %chr)
+  store ptr %dst, ptr @chp
+  ret void
+}
+
+; CHECK: declare double @ldexp(double, i32 signext)
+; CHECK: declare float @ldexpf(float, i32 signext)
+; CHECK: declare fp128 @ldexpl(fp128, i32 signext)
+; CHECK: declare ptr @memccpy(ptr noalias writeonly, ptr noalias nocapture readonly, i32 signext, i64)
+; CHECK: declare noundef i32 @fputc(i32 noundef signext, ptr nocapture noundef)
+; CHECK: declare noundef i32 @putchar(i32 noundef signext)
+; CHECK: declare ptr @memchr(ptr, i32 signext, i64)