Merge fixed alloca stack adjustments into the prolog

tests_lit/llvm2ice_tests/fused-alloca.ll

 ; This is a basic test of the alloca instruction.
 
 ; RUN: %if --need=target_X8632 --command %p2i --filetype=obj --disassemble \
 ; RUN:   --target x8632 -i %s --args -O2 -allow-externally-defined-symbols \
 ; RUN:   | %if --need=target_X8632 --command FileCheck %s
 
 ; Test that a sequence of allocas with less than stack alignment get fused.
 define internal void @fused_small_align(i32 %arg) {
 entry:
   %a1 = alloca i8, i32 8, align 4
   %a2 = alloca i8, i32 12, align 4
   %a3 = alloca i8, i32 16, align 8
   %p1 = bitcast i8* %a1 to i32*
   %p2 = bitcast i8* %a2 to i32*
   %p3 = bitcast i8* %a3 to i32*
   store i32 %arg, i32* %p1, align 1
   store i32 %arg, i32* %p2, align 1
   store i32 %arg, i32* %p3, align 1
   ret void
 }
 ; CHECK-LABEL: fused_small_align
-; CHECK-NEXT: sub    esp,0xc
-; CHECK-NEXT: mov    eax,DWORD PTR [esp+0x10]
 ; CHECK-NEXT: sub    esp,0x30
-; CHECK-NEXT: mov    {{.*}},esp
+; CHECK-NEXT: mov    eax,DWORD PTR [esp+0x34]
 ; CHECK-NEXT: mov    DWORD PTR [esp+0x10],eax
 ; CHECK-NEXT: mov    DWORD PTR [esp+0x18],eax
 ; CHECK-NEXT: mov    DWORD PTR [esp],eax
-; CHECK-NEXT: add    esp,0x3c
+; CHECK-NEXT: add    esp,0x30
 
 ; Test that a sequence of allocas with greater than stack alignment get fused.
 define internal void @fused_large_align(i32 %arg) {
 entry:
   %a1 = alloca i8, i32 8, align 32
   %a2 = alloca i8, i32 12, align 64
   %a3 = alloca i8, i32 16, align 32
   %p1 = bitcast i8* %a1 to i32*
   %p2 = bitcast i8* %a2 to i32*
   %p3 = bitcast i8* %a3 to i32*
   store i32 %arg, i32* %p1, align 1
   store i32 %arg, i32* %p2, align 1
   store i32 %arg, i32* %p3, align 1
   ret void
 }
 ; CHECK-LABEL: fused_large_align
 ; CHECK-NEXT: push   ebp
 ; CHECK-NEXT: mov    ebp,esp
-; CHECK-NEXT: sub    esp,0x8
+; CHECK-NEXT: sub    esp,0x80
+; CHECK-NEXT: and    esp,0xffffffc0
 ; CHECK-NEXT: mov    eax,DWORD PTR [ebp+0x8]
-; CHECK-NEXT: and    esp,0xffffffc0
-; CHECK-NEXT: sub    esp,0x80
-; CHECK-NEXT: mov    ecx,esp
 ; CHECK-NEXT: mov    DWORD PTR [esp+0x40],eax
 ; CHECK-NEXT: mov    DWORD PTR [esp],eax
 ; CHECK-NEXT: mov    DWORD PTR [esp+0x60],eax
 ; CHECK-NEXT: mov    esp,ebp
 ; CHECK-NEXT: pop    ebp
 
 ; Test that an interior pointer into a rematerializable variable is also
 ; rematerializable, and test that it is detected even when the use appears
 ; syntactically before the definition.  Test that it is folded into mem
 ; operands, and also rematerializable through an lea instruction for direct use.
@@ skipping 10 matching lines @@
   ret i32 %retval
 block2:
 ; The following are all rematerializable variables deriving from %a2.
   %p2 = ptrtoint i8* %a2 to i32
   %d = add i32 %p2, 12
   %retval = add i32 %p2, 1
   %derived = inttoptr i32 %d to i32*
   br label %block1
 }
 ; CHECK-LABEL: fused_derived
-; CHECK-NEXT: sub    esp,0xc
-; CHECK-NEXT: mov    [[ARG:e..]],DWORD PTR [esp+0x10]
 ; CHECK-NEXT: sub    esp,0x180
-; CHECK-NEXT: mov    {{.*}},esp
+; CHECK-NEXT: mov    [[ARG:e..]],DWORD PTR [esp+0x184]
 ; CHECK-NEXT: jmp
 ; CHECK-NEXT: mov    DWORD PTR [esp+0x80],[[ARG]]
 ; CHECK-NEXT: mov    DWORD PTR [esp+0x8c],[[ARG]]
 ; CHECK-NEXT: lea    eax,[esp+0x81]
-; CHECK-NEXT: add    esp,0x18c
+; CHECK-NEXT: add    esp,0x180
 ; CHECK-NEXT: ret
+
+; Test that a fixed alloca gets referenced by the frame pointer.
+define internal void @fused_small_align_with_dynamic(i32 %arg) {
+entry:
+  %a1 = alloca i8, i32 8, align 16
+  br label %next
+next:
+  %a2 = alloca i8, i32 12, align 1
+  %a3 = alloca i8, i32 16, align 1
+  %p1 = bitcast i8* %a1 to i32*
+  %p2 = bitcast i8* %a2 to i32*
+  %p3 = bitcast i8* %a3 to i32*
+  store i32 %arg, i32* %p1, align 1
+  store i32 %arg, i32* %p2, align 1
+  store i32 %arg, i32* %p3, align 1
+  ret void
+}
+; CHECK-LABEL: fused_small_align_with_dynamic
+; CHECK-NEXT: push   ebp
+; CHECK-NEXT: mov    ebp,esp
+; CHECK-NEXT: sub    esp,0x18
+; CHECK-NEXT: mov    eax,DWORD PTR [ebp+0x8]
+; CHECK-NEXT: sub    esp,0x10
+; CHECK-NEXT: mov    ecx,esp
+; CHECK-NEXT: sub    esp,0x10
+; CHECK-NEXT: mov    edx,esp
+; CHECK-NEXT: mov    DWORD PTR [ebp-0x18],eax
+; CHECK-NEXT: mov    DWORD PTR [ecx],eax
+; CHECK-NEXT: mov    DWORD PTR [edx],eax
+; CHECK-NEXT: mov    esp,ebp
+; CHECK-NEXT: pop    ebp
+
+; Test that a sequence with greater than stack alignment and dynamic size
+; get folded and referenced correctly;
+
+define internal void @fused_large_align_with_dynamic(i32 %arg) {
+entry:
+  %a1 = alloca i8, i32 8, align 32
+  %a2 = alloca i8, i32 12, align 32
+  %a3 = alloca i8, i32 16, align 1
+  %a4 = alloca i8, i32 16, align 1
+  br label %next
+next:
+  %a5 = alloca i8, i32 16, align 1
+  %p1 = bitcast i8* %a1 to i32*
+  %p2 = bitcast i8* %a2 to i32*
+  %p3 = bitcast i8* %a3 to i32*
+  %p4 = bitcast i8* %a4 to i32*
+  %p5 = bitcast i8* %a5 to i32*
+  store i32 %arg, i32* %p1, align 1
+  store i32 %arg, i32* %p2, align 1
+  store i32 %arg, i32* %p3, align 1
+  store i32 %arg, i32* %p4, align 1
+  store i32 %arg, i32* %p5, align 1
+  ret void
+}
+; CHECK-LABEL: fused_large_align_with_dynamic
+; CHECK-NEXT: push   ebx
+; CHECK-NEXT: push   ebp
+; CHECK-NEXT: mov    ebp,esp
+; CHECK-NEXT: sub    esp,0x64
+; CHECK-NEXT: mov    eax,DWORD PTR [ebp+0xc]
+; CHECK-NEXT: and    esp,0xffffffe0
+; CHECK-NEXT: sub    esp,0x40
+; CHECK-NEXT: mov    ecx,esp
+; CHECK-NEXT: mov    edx,ecx
+; CHECK-NEXT: add    edx,0x20
+; CHECK-NEXT: add    ecx,0x0
+; CHECK-NEXT: sub    esp,0x10
+; CHECK-NEXT: mov    ebx,esp
+; CHECK-NEXT: mov    DWORD PTR [ecx],eax
+; CHECK-NEXT: mov    DWORD PTR [edx],eax
+; CHECK-NEXT: mov    DWORD PTR [ebp-0x14],eax
+; CHECK-NEXT: mov    DWORD PTR [ebp-0x24],eax
+; CHECK-NEXT: mov    DWORD PTR [ebx],eax
+; CHECK-NEXT: mov    esp,ebp
+; CHECK-NEXT: pop    ebp