[X86] Fix Windows `i1 zeroext` conventions to use i8 instead of i32
Summary:
Re-lands r328386 and r328443, reverting r328482.
Incorporates fixes from @mstorsjo in D44876 (thanks!) so that small
parameters in i8 and i16 do not end up in the SysV register parameters
(EDI, ESI, etc).
I added tests for how we receive small parameters, since that is the
important part. It's always safe to store more bytes than will be read,
but the assumptions you make when loading them are what really matter.
I also tested this by self-hosting clang and it passed tests on win64.
Reviewers: mstorsjo, hans
Subscribers: hiraditya, mstorsjo, llvm-commits
Differential Revision: https://reviews.llvm.org/D44900
llvm-svn: 328570
diff --git a/llvm/test/CodeGen/X86/win-smallparams.ll b/llvm/test/CodeGen/X86/win-smallparams.ll
new file mode 100644
index 0000000..93b528a
--- /dev/null
+++ b/llvm/test/CodeGen/X86/win-smallparams.ll
@@ -0,0 +1,67 @@
+; When we accept small parameters on Windows, make sure we do not assume they
+; are zero or sign extended in memory or in registers.
+
+; RUN: llc < %s -mtriple=x86_64-windows-msvc | FileCheck %s --check-prefix=WIN64
+; RUN: llc < %s -mtriple=x86_64-windows-gnu | FileCheck %s --check-prefix=WIN64
+; RUN: llc < %s -mtriple=i686-windows-msvc | FileCheck %s --check-prefix=WIN32
+; RUN: llc < %s -mtriple=i686-windows-gnu | FileCheck %s --check-prefix=WIN32
+
+define void @call() {
+entry:
+ %rv = call i32 @manyargs(i8 1, i16 2, i8 3, i16 4, i8 5, i16 6)
+ ret void
+}
+
+define i32 @manyargs(i8 %a, i16 %b, i8 %c, i16 %d, i8 %e, i16 %f) {
+entry:
+ %aa = sext i8 %a to i32
+ %bb = sext i16 %b to i32
+ %cc = zext i8 %c to i32
+ %dd = zext i16 %d to i32
+ %ee = zext i8 %e to i32
+ %ff = zext i16 %f to i32
+ %t0 = add i32 %aa, %bb
+ %t1 = add i32 %t0, %cc
+ %t2 = add i32 %t1, %dd
+ %t3 = add i32 %t2, %ee
+ %t4 = add i32 %t3, %ff
+ ret i32 %t4
+}
+
+; WIN64-LABEL: call:
+; WIN64-DAG: movw $6, 40(%rsp)
+; WIN64-DAG: movb $5, 32(%rsp)
+; WIN64-DAG: movb $1, %cl
+; WIN64-DAG: movw $2, %dx
+; WIN64-DAG: movb $3, %r8b
+; WIN64-DAG: movw $4, %r9w
+; WIN64: callq manyargs
+
+; WIN64-LABEL: manyargs:
+; WIN64-DAG: movsbl %cl,
+; WIN64-DAG: movswl %dx,
+; WIN64-DAG: movzbl %r8b,
+; WIN64-DAG: movzwl %r9w,
+; WIN64-DAG: movzbl 40(%rsp),
+; WIN64-DAG: movzwl 48(%rsp),
+; WIN64: retq
+
+
+; WIN32-LABEL: _call:
+; WIN32: pushl $6
+; WIN32: pushl $5
+; WIN32: pushl $4
+; WIN32: pushl $3
+; WIN32: pushl $2
+; WIN32: pushl $1
+; WIN32: calll _manyargs
+
+; WIN32-LABEL: _manyargs:
+; WIN32-DAG: movsbl 4(%esp),
+; WIN32-DAG: movswl 8(%esp),
+; WIN32-DAG: movzbl 12(%esp),
+; WIN32-DAG: movzwl 16(%esp),
+; WIN32-DAG: movzbl 20(%esp),
+; WIN32-DAG: movzwl 24(%esp),
+; WIN32: retl
+